Note: Descriptions are shown in the official language in which they were submitted.
2126252
PATENT
ABSORBENT ARTICLE HAVING AN IMPROVED ADHESIVE SECUREMENT PATTERN
FIELD OF THE INVENTION
5This invention relates to an absorbent article for absorbing
body fluids which is designed to be positioned in the crotch portion
of an undergarment. More specifically, the invention relates to an
absorbent article having an improved garment adhesive pattern which
substantially forms a diamond shape.
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BACKGROUND OF THE INVENTION
Currently, a wide variety of products for absorption of human
body fluids are available in the form of feminine pads, sanitary
napkins, panty shields, panty liners, incontinence devices, etc.
These products generally have an absorbent positioned between a
liquid-permeable bodyside cover and a liquid-impermeable
undergarment-facing baffle. A pressure-sensitive adhesive which is
secured to the baffle is generally used to attach the product to an
undergarment's inner crotch portion, also known as the shadow panel
of the undergarment. Such adhesively attached absorbent products
have met with significant commercial success.
However, each of the structures proposed in the art suffer from
certain disadvantages which dictate against ready acceptance by the
user. For example, shifting of the absorbent article from its
original position on the supporting undergarment during use. This
can be attributed to periodic release and reattachment of the
adhesive as shear forces are exerted on the pad and the garment
during normal body movement.
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It has been recognized by those skilled in the art that
particular placement of the garment attachment adhesive along the
undergarment-facing side of the baffle determines, to a large extent,
both the effectiveness of the adhesive attachment and the comfort of
the article to the wearer. A variety of adhesive placement
configurations have been taught in the past. One adhesive
configuration includes using one or more bands of adhesive typically
placed along the longitudinal axis of the absorbent article. Other
configurations include various designs such as an "X", chevrons and
arcuate strips that are parallel to the article's perimeter. It has
been observed that the aforementioned designs generally consist of
bands of adhesive which may have unequal length and width dimensions.
It has also been recognized that a sanitary napkin is subje. ed
to side crushing forces by the thighs. These forces tend to
permanently distort the napkin along each longitudinal edge. This
crushing of the sanitary napkin can, in some cases,~not only dislodge
the napkin from its secured position, but can also distort the back
surface of the napkin. The distortion can cause adhesive that is
centrally disposed on the absorbent article to contact each other,
preventing the napkin from reattaching to the undergarment. The side
crushing forces can also cause the sanitary napkin to remain in a
contorted position, diminishing the napkin's efficacy.
While there are several different prior art configurations for
adhesively securing a sanitary napkin to an undergarment, none of the
prior art configurations provide the advantages of the adhesive
pattern disclosed herein.
There is, therefore, a need for developing a superior adhesive
pattern which would provide secure attachment of an absorbent article
to the crotch portion of an undergarment and provide for reduced
bunching and twisting of the absorbent article during its use.
SUMMARY OF THE INVENTION
Briefly, this invention relates to an absorbent article having
an absorbent and an adhesive means for securing the absorbent article
to the crotch portion of a wearer's undergarment. The adhesive means
includes a plurality of spaced apart adhesive members which, if
extended, would substantially form a diamond pattern. The diamond
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pattern has a pair of apexes aligned along the longitudinal axis of
the absorbent and a pair of apexes aligned along the transverse axis
of the absorbent. The adhesive members also are spaced a distance of
at least 3 millimeters from the longitudinal axis of the absorbent.
The general object of this invention is to provide an absorbent
article for absorbing body fluids. A more specific object of this
invention is to provide an absorbent article, such as a sanitary
napkin, with an improved garment attachment means that reduces
bunching, twisting and folding of the napkin during use.
Another object of the invention is to provide an adhesive
pattern that allows the absorbent article to adapt to tortious forces
caused by normal body movement of the wearer.
It is another object of this invention to provide an absorbent
article which adheres well to the crotch area of an undergarment but
that also be easily removed for disposal.
Other objects and advantages of the present invention will
become more apparent to those skilled in the art in view of the
following description and the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
Figure 1 is a partial cutaway perspective view of an absorbent
article having the garment side facing upward and showing 4 spaced
apart adhesive members substantially forming a diamond pattern.
Figure 2 is a perspective view illustrating how the adhesive
members become substantially linear in responding to lateral forces,
similar to those in use, compressing the absorbent article.
Figure 3 is a perspective view similar to that of Figure 1
illustrating the adhesive members being continuous from end-to-end
but spaced from the longitudinal axis of the absorbent article.
Figure 4 is a perspective view similar to that of Figure 1
showing two adhesive elements, as represented by dots, aligned along
the absorbent's longitudinal axis and separated from the adhesive
members which form a diamond pattern.
Figure 5 is a perspective view of an alternative embodiment of
the invention showing similarly configured adhesive elements that are
spaced apart and are arranged substantially in a diamond pattern.
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-~ Figure 6 is a perspective view similar to that illustrated in
Figure 5 except the adhesive elements are circular in design.
Figure 7 is a perspective view similar to that illustrated in
Figure 5 except that the adhesive elements are interconnected,
diamond shapes.
Figure 8 is an enlarged view of the circled area of Figure 7.
Figure 9 is a perspective view of an alternative embodiment of
the invention showing adhesive members which extend the length of the
absorbent and have an arcuate shape.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
Referring to Figs. 1-3, an absorbent article 10 is depicted
having its garment-facing surface facing upward. For ease in
description the numbers corresponding to similar components in the
figures are designated identically. The absorbent article 10 can be
a feminine pad, a sanitary napkin, a panty shield, ~ panty liner, an
incontinence device, etc. The absorbent article 10 is depicted as
having a racetrack design but it can be oval, hourglass, or any other
shape that is known in the disposable absorbent article art. The
absorbent article 10 includes an absorbent 12 having a longitudinal
axis (X--X) and a transverse axis (Y--Y), a pair of longitudinal
sides 14 and 15, and a first end 16 and a distal second end 18. The
absorbent 12 also has a predetermined thickness, as measured along
the axis Z--Z. A liquid-impermeable baffle 20 is positioned adjacent
to at least one side of the absorbent 12. Typically, the absorbent
article 10 includes a liquid-permeable cover 22 positioned adjacent
to the absorbent 12.
The absorbent 12 can be any suitable absorbent material such as
comminuted wood pulp fibers, absorbent polymer filaments such as
polypropylene, devilicated wood fibers, rayon fibers, cotton staple,
cotton linters and polyester. One of ordinary skill in the art will
understand that any of the number of different materials may be used
for the layer described above. Moreover, numerous other absorbent
constructions comprising greater, fewer or different types of layers
are well known within the personal absorbent products art. Thus, it
is understood that the present invention is not limited to the type
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~ of absorbent products with which it is to be used, nor is it limited
to the construction of the absorbent itself.
The liquid-impermeable baffle 20 can be designed to permit the
passage of air or vapor out of the absorbent article 10 while
blocking the passage of liquids. The baffle 20 can be made from any
material having these properties. A good material is polyethylene.
A microembossed, polymeric film, such as polyethylene or
polypropylene also works well. Bicomponent films can also be used.
Most preferably, the baffle 20 will be a polyethylene film having a
thickness in the range of about 0.2 to about 2.0 millimeters,
preferably about 0.3 to 1.0 millimeter.
The liquid-permeable cover 22 cooperates with the baffle 20 to
enclose the absorbent 12. As illustrated in Fig. 1, the baffle 20,
the absorbent 12 and the cover 22 have coterminous edges, but this is
not required. The invention may be advantageously applied to all
kinds of adhesively attached absorbent articles. The
liquid-permeable cover 22 is designed to contact the body of the
wearer. It can be constructed from natural or synthetic materials
including woven, nonwoven, apertured films or a combination thereof.
The cover should be easily penetrated by body fluid. Suitable
materials include bonded, carded webs of polyester, polypropylene,
polyethylene, nylon or other bondable fibers. Other materials
include tissue, perforated film or netting.
The absorbent article 10 has an adhesive 24 positioned on the
baffle 20. The adhesive 24 secures the absorbent article 10 to the
crotch portion of a wearer's undergarment and prevents the absorbent
article 10 from sliding out of position relative to a woman's vulva.
The adhesive 24 includes elongated adhesive strips forming a
plurality of spaced apart adhesive members 26, which if extended,
substantially form a diamond pattern. As used herein the term
"diamond pattern" is defined as any quadrilateral having its
diagonals substantially vertical and horizontal. As used herein the
term "substantially vertical and horizontal" means that the
horizontal and vertical diagonals of the diamond can intersect with a
variance of about 20 degrees from a right angle. However, it is
critical to the invention that the adhesive members 26 be spaced
apart from the longitudinal axis X--X, i.e., not interconnected along
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the longitudinal axis X--X of the absorbent 12. Preferably, at the
first or second ends 16 or 18, respectively, the adhesive members 26
are spaced from the longitudinal axis X--X a distance of from about 3
millimeters to about 20 millimeters, more preferably from about 5
millimeters to about 15 millimeters, and most preferably from about 7
millimeters to about 12 millimeters. It is believed that this
feature allows the absorbent article 10 to bec~me, generally,
linearly aligned with the wearer to accommodate "in use" motions. It
can also reduce the discomfort and leakage caused by pad distortions
commonly known as bunching, roping, twisting and folding of the
absorbent article 10. As used herein the term "in use" means the
position and orientation of the absorbent article when placed in the
crotch portion of an undergarment as being worn by the user.
Referring to Figure 2, the adhesive members 26 of the absorbent
article 10 are shown as becoming aligned substantially along the
longitudinal axis X--X or approximately parallel to~the longitudinal
axis X--X in response to lateral compressional forces Fc. These
forces typically are exerted on the absorbent 12 during use. One of
ordinary skill in the art will understand that the extent the
adhesive members 26 become aligned is dependent upon the degree of
lateral compressive forces Fc. The greater the force, the greater
the adhesive members 26 will move inward to align themselves with the
longitudinal axis X--X.
Referring again to Figure 1, the adhesive diamond pattern has a
pair of transverse apexes 28 and 29 that are located adjacent to the
longitudinal sides 14 and 15 respectively, of the absorbent 12. The
adhesive diamond pattern also includes a pair of longitudinal
apexes 30 and 31 that are located adjacent to the first end 16 and
the second end 18, respectively, of the absorbent 12. Since the
arrangement of the adhesive members 26 along the longitudinal axis
X--X of the absorbent 12 are similar, only one side will be
described.
As shown in Fig. 1, the transverse apex 28 and the longitudinal
apex 30 of the diamond pattern are aligned along the transverse axis
Y--Y and the longitudinal axis X--X respectively. It is not
necessary for the transverse apex 28 to be aligned with the
transverse axis Y--Y of the absorbent 12. The adhesive members 26
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forming the diamond pattern can be spaced apart from the transverse
axis Y--Y a distance of from about 1 millimeter to about 20
millimeters.
The transverse apex 28 of the diamond pattern is located inward
from the longitudinal side 14 of the absorbent 12 a distance of from
about 3 millimeters to about 20 millimeters and preferably, a
distance at least equal to the width of the absorbent 12. Although
independently spaced, the longitudinal apex 30 can be spaced from the
first end 16 a distance of 3 millimeters to about 20 millimeters.
The dimensions of the adhesive members 26 generally range from
about 0.2 millimeters to about 20 millimeters in width, preferably
from about 0.5 millimeters to about 8 millimeters and most preferably
from about 0.8 millimeters to about 5 millimeters. Alternative~ ,
the width of the adhesive members 26 can be from about 5 percent to
about 20 percent of the width of the absorbent 12. Their length is
generally from 5 millimeters to about 120 millimeters but this is
governed by the dimensions of the absorbent 12 used in the absorbent
article 10.
The adhesive members 26 can be made from any number of pressure
sensitive adhesives readily available and currently known to those
skilled in the pressure sensitive, garment adhesive art. A water
based pressure sensitive adhesive such as vinyl acetate-2 ethyl hexyl
acrylate copolymer which is generally combined with a tackifier such
as, ethylene amine. A~ternatively, the adhesive may be a rapid
setting thermoplastic adhesive such as a block copolymer. Block
copolymers include styrene and butadiene styrene copolymers. The
adhesive members 26 may also comprise a two-sided adhesive tape which
are known in the adhesive art.
The adhesive used in forming the adhesive members 26 is attached
to the baffle 20 by means of conventional application methods. One
method includes directly applying the adhesive to the baffle 20 in
the desired arrangement. Another method is by applying to the
absorbent 12 one or more protective films which have been provided
with still moist adhesive on their absorbent 12 facing side.
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~ Referring to Figure 3, an alternative embodiment is shown. The
adhesive members 26 are similar to those described above except that
the adhesive members 26 intersect. Preferably, the adhesive
members 26 intersect at the transverse axis Y--Y of the absorbent 12.
Thus, the absorbent article 10 has continuous adhesive members 26 on
the baffle 20.
Referring to Fig. 4, an alternative embodiment is shown wherein
the adhesive pattern is similar to that illustrated in Fig. 3 except
that a pair of adhesive elements 32 and 33, are depicted. The
adhesive elements 32 and 33 each have a circular configuration, but
are not limited to this shape. The adhesive elements 32 and 33 are
aligned along the longitudinal axis X--X of the absorbent 12. The
adhesive elements 32 and 33 provide additional adhesive surface area
in the first end 16 and second end 18 of the absorbent 12 to prevent
the absorbent article 10 from shifting in the longitudinal direction.
The adhesive elements 32 and 33 are spaced apart frOm the
longitudinal apex 30 of the absorbent 12 a distance of from about 1
millimeter to about 10 millimeters and preferably from about 4
millimeters to about 8 millimeters.
Referring to Figure 5, the adhesive elements 36 are shown as
rectangular or square in configuration. As used herein, the term
"adhesive elements" means, and is distinguishable from "adhesive
members," in that it requires more than one adhesive element 36 to
traverse the distance that would form one side of the diamond
pattern. The distance is measured from the longitudinal side 14 or
15 at the transverse axis Y--Y of the absorbent 12 extending to the
first or second ends 16 or 18, respectively, of the absorbent 12.
Generally, the adhesive elements are spaced apart from each other by
a distance ranging from about 1 millimeter to about 5 millimeters and
preferably from about 2 millimeters to about 5 millimeters. The size
of the adhesive elements 36 have a width as described above and can
have a length ranging from about 3 millimeters to about 12
millimeters and preferably from about 4 millimeters to about 8
millimeters.
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The adhesive elements 36 are linearly aligned and extend from
the longitudinal sides 14 and 15 to the first and second ends, 16 and
18 respectively, substantially forming a diamond pattern. The
adhesive elements 36 are preferably similarly configured. The
adhesive elements 36 can be any geometric configuration which allows
the adhesive elements 36 to become linearly aligned or near linearly
aligned when lateral compression forces are exerted on the absorbent.
Referring to Fig. 6, an alternative embodiment is shown. The
adhesive elements 38 are similar to those described above except that
they are circular in configuration. The diameter of the adhesive
elements 38 ranges in size of from about 2 millimeters to about 12
millimeters.
Referring to Figs. 7 and 8, another alternative embodiment of
this invention is shown. The adhesive elements 40 are depicted as
having a diamond configuration wherein the longitudinal apexes 42 of
each diamond are interconnected. The width and length of an adhesive
element 40 is similar to that described above for adhesive
element 36. As best seen in Fig. 8, the length dimension of an
adhesive element 40 is measured along the longitudinal axis X'--X'
and the width is measured along the transverse axis Y'--Y'.
Referring to Figure 9, an alternative embodiment of the
absorbent article 10' is shown. The adhesive members 26' forming the
diamond pattern are arcuate in shape but otherwise are similar to the
adhesive members 26 described above.
Referring again to Fig. 4, overlying the full length of the
adhesive members 26 is a protective release strip 44 which is
provided to protect the adhesive 24 from dirt and from unintended
adhesion prior to use. The strip 44 may be any suitable sheet-like
material which adhere with sufficient tenacity to the adhesive
members 26 to remain in place, but which can be readily removed when
the absorbent article 10 is to be used. A particularly useful
material is a semi-bleached kraft paper, the adhesive contacting side
of which has been silicone coated to provide for easy release from
the adhesive.
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When a person is ready to use the product, the peel strip 44 is
removed, exposing the garment adhesive 24. The absorbent article 10
is attached to the inner surface of the crotch portion of the
wearer's undergarment so as to hold the absorbent article 10 firmly
in place.
While the invention has been described in conjunction with
several specific embodiments, it is to be understood that many other
alternatives, modifications and variations will be apparent to those
skilled in the art in light of the foregoing description.
Accordingly, this invention is intended to embrace all such
alternatives, modifications and variations which fall within the
spirit and scope of the appended claims.
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