U.S. patent application number 10/100864 was filed with the patent office on 2002-09-19 for tampon having an apertured film cover.
Invention is credited to Gell, Carol, Pierson, Linda, Yeganeh, Mary.
Application Number | 20020133135 10/100864 |
Document ID | / |
Family ID | 26731038 |
Filed Date | 2002-09-19 |
United States Patent
Application |
20020133135 |
Kind Code |
A1 |
Gell, Carol ; et
al. |
September 19, 2002 |
Tampon having an apertured film cover
Abstract
An absorbent tampon has improved ease of insertion into and
removal from a body cavity. This is accomplished by covering at
least a portion of the outer surface of the tampon with an
apertured polymeric formed film. The apertured formed film provides
a smooth land area on the outermost surface of the tampon for
gentle, nondrying passage along the vaginal walls. The apertures in
the film allow fluid to pass through the cover and into the
absorbent core, where the fluid is held to prevent leakage.
Inventors: |
Gell, Carol; (Belle Mead,
NJ) ; Pierson, Linda; (Somerville, NJ) ;
Yeganeh, Mary; (Piscataway, NJ) |
Correspondence
Address: |
AUDLEY A. CIAMPORCERO JR.
JOHNSON & JOHNSON
ONE JOHNSON & JOHNSON PLAZA
NEW BRUNSWICK
NJ
08933-7003
US
|
Family ID: |
26731038 |
Appl. No.: |
10/100864 |
Filed: |
March 19, 2002 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
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10100864 |
Mar 19, 2002 |
|
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09097555 |
Jun 15, 1998 |
|
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60052752 |
Jun 30, 1997 |
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Current U.S.
Class: |
604/385.18 ;
28/118; 604/904 |
Current CPC
Class: |
A61F 13/2068 20130101;
Y10S 604/904 20130101; A61F 13/2085 20130101 |
Class at
Publication: |
604/385.18 ;
604/904; 28/118 |
International
Class: |
A61F 013/15; D04H
001/22; A61F 013/20 |
Claims
What is claimed is:
1. A tampon comprising a generally elongated absorbent core
comprising absorbent material, and an outer cover comprising an
apertured polymeric formed film, the apertured polymeric formed
film comprising a land region having a multiplicity of openings
therein; each said opening being defined by a first aperture and
sidewalls extending in a substantially uniform direction from the
first aperture and terminating in a second aperture; and open area
formed cumulatively by the second apertures comprising less than
about 35% of the surface area of the apertured polymeric formed
film; wherein the outer cover is oriented on the tampon such that
the second apertures are adjacent the absorbent core.
2. The tampon of claim 1 wherein at least a portion of the second
apertures are bridged by polymeric fibrils.
3. The tampon of claim 2 wherein at least 50% of the second
apertures are bridged by polymeric fibrils.
4. The tampon of claim 1 wherein the absorbent core has at least
one generally elongated surface, the outer cover being present over
a substantial portion of the at least one generally elongated
surface.
5. The tampon of claim 4 wherein the absorbent core has two end
surfaces, at least one end surface being substantially covered by
the outer cover.
6. The tampon of claim 1 wherein the absorbent core comprises
absorbent fibers.
7. The tampon of claim 1 wherein the apertured polymeric formed
film comprises a blend of ethylene-vinyl acetate and
polypropylene.
8. The tampon of claim 1 wherein the apertured polymeric formed
film comprises a blend of polypropylene and low density
polyethylene.
9. The tampon of claim 1 wherein the absorbent core is generally
cylindrical.
10. The tampon of claim 1 wherein the open area comprises about 2%
to about 35% of the surface area of the apertured polymeric formed
film.
11. The tampon of claim 10 wherein the open area comprises about 2%
to about 25% of the surface area of the apertured polymeric formed
film.
12. A method of making a tampon having a generally elongated
absorbent core and an outer cover of apertured polymeric formed
film, the method comprising: forming a portion of absorbent
material into a generally elongated blank having a generally
elongated surface and two end surfaces; applying a length of
apertured polymeric formed film to the absorbent material such that
the film substantially covers the generally elongated surface to
form a covered blank; attaching a withdrawal cord to the blank; and
compressing the covered blank.; wherein the apertured polymeric
formed film comprises a land region having a multiplicity of
openings therein, each said opening being defined by a first
aperture, and sidewalls extending in a uniform direction and
terminating in a second aperture; and open area formed cumulatively
by the second apertures comprising less than about 35% of the
surface area of the apertured polymeric formed film.
13. The method of claim 12 wherein the length of apertured
polymeric formed film is applied before the absorbent material is
formed into a generally elongated blank.
14. The method of claim 13 wherein the length of apertured
polymeric formed film is applied after the absorbent material is
formed into a generally elongated blank.
15. The method of claim 12 wherein the length of apertured
polymeric formed film further covers at least one end surface.
16. The method of claim 12 wherein the absorbent core is generally
cylindrical.
Description
FIELD OF THE INVENTION
[0001] The present invention relates to a generally elongated
tampon for insertion into a mammalian body cavity. These tampons
have smooth, apertured polymeric formed film covers to provide for
smooth gentle insertion into and removal from a body cavity.
BACKGROUND OF THE INVENTION
[0002] Catamenial tampons are used by women to absorb the flow of
menstrual fluids to prevent leakage and staining of undergarments,
and other clothing. Therefore, it is desirable for tampons to
demonstrate good absorbency and to be able to absorb fluid quickly.
Unfortunately, tampons are not without disadvantages and
inconveniences. For example, tampons may unexpectedly leak if they
do not expand quickly enough or fully enough to fill the vaginal
canal. Tampons are also sometimes difficult or uncomfortable to
insert into or remove from the vaginal canal. These insertion and
removal difficulties may be especially apparent when the menstrual
flow is light.
[0003] There have been many attempts to remedy these problems by
altering the absorbent material or the outer cover of the tampon.
Greiner et al., U.S. Pat. No. 2,710,007, and Burgeni, U.S. Pat. No.
3,340,874, are examples of the use of low density material in
portions of a tampon to promote rapid fluid absorption. Gellert,
U.S. Pat. No. 4,475,911, describes a tampon made up of an unbonded
array of nonabsorbent, hydrophilic, resilient fibers completely
enclosed within a porous overwrap of apertured formed film.
[0004] Thompson, U.S. Pat. No. 3,929,135, describes a topsheet
useful in disposable absorptive devices, including catamenial
tampons. The topsheet is an apertured formed film having tapered
capillaries. The Examples in this reference describe a topsheet
having a top surface which is more than about 90% open area.
[0005] Lloyd et al., U.S. Pat. No. 5,374,258, describes a tampon
with a cover comprising lengthwise ribs. The ribs on the cover are
parallel to the tampon's axis and are separated from one another by
multiple transverse ribs. Howarth, U.S. Pat. No. 5,403,300,
describes a tampon with a polymer net outer cover. The net
comprises two intersecting sets of parallel ribs which are aligned
obliquely with respect to the main axis of the tampon and to each
other. The orientation of the ribs allegedly aids in the smooth
insertion and removal of the tampon.
[0006] Commonly assigned, copending patent application to Foley et
al., U.S. Pat. application Ser. No. 08/789,747 (also published as
EP 685 215) describes a tampon which demonstrates low capillary
suction pressure on the vaginal epithelium. The contents of this
application are hereby incorporated herein by reference.
[0007] It is an object of this invention to provide a novel tampon
with good absorbency and leakage protection, ease of insertion into
and removal from a body cavity, and a relatively clean dry surface
after use.
SUMMARY OF THE INVENTION
[0008] The tampons of this invention provide good absorbency and
protection from leakage while providing a smooth surface for easy,
gentle insertion into and removal from the vaginal canal. They
accomplish this by providing a generally elongated absorbent core
made from absorbent materials, and an outer cover made from an
apertured formed film. The apertured polymeric formed film
comprises a land region having a multiplicity of openings therein.
Each of these openings is defined by a first aperture and sidewalls
extending in a uniform direction from the first aperture. The side
walls terminate in a second aperture. The open area formed
cumulatively by the second apertures comprises less than about 35%
of the surface area of the apertured polymeric formed film. The
outer cover is oriented on the tampon such that the second
apertures are adjacent the absorbent core.
[0009] The apertured formed film provides a generally smooth land
area on the outermost surface of the tampon for gentle, nondrying
passage along the vaginal walls. The apertures in the film allow
fluid to pass through the cover and into the absorbent core, where
the fluid is held to prevent leakage.
[0010] The tampon of the invention may be made by forming a
generally elongated blank of absorbent material, attaching a length
of apertured polymeric formed film so that it covers at least the
generally elongated surface of the blank, and then compressing the
covered blank to form a tampon. A withdrawal cord or string may be
attached to the blank or the covered blank to aid a user in
withdrawing the tampon from a body cavity after use.
BRIEF DESCRIPTION OF THE DRAWINGS
[0011] FIG. 1 illustrates a perspective view of a preferred
embodiment of a tampon of the invention.
[0012] FIG. 1A illustrates an exploded cross-sectional view of the
apertured film of FIG. 1.
[0013] FIG. 2 is a side view of a tampon of the prior art with
fibers protruding through the cover.
[0014] FIG. 3 is a side view of a tampon of this invention.
[0015] FIG. 4 is a graph illustrating the frequency of the
distances of "Nearest Neighbor" apertures ("NNDIST") in a preferred
embodiment of an outer cover for the tampon of the invention.
[0016] FIG. 5 is a graph illustrating the frequency of the
distances of "Nearest Neighbor" apertures ("NNDIST") in a fibrous
cover for a commercially available o.b..RTM. tampon.
[0017] FIG. 6 is a diagrammatic view of a preferred type of
apparatus for producing apertured formed film for use on the tampon
of the present invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
[0018] As shown in FIGS. 1 and 1A, a preferred embodiment of the
tampon 10 of the invention has a generally elongated absorbent core
12 of absorbent materials and an outer cover 14 of apertured formed
film. The apertured formed film of the cover 14, when arranged in a
substantially planar orientation, comprises a land region 16 having
multiple openings 18 therein. Each opening 18 has a first aperture
20 in the land region 16 and side walls 22 extending therefrom in a
substantially uniform direction and terminating in second apertures
24. It is not necessary that all of the second apertures 24 lie
within the same plane.
[0019] Some of the second apertures 24 may be split by bridging
fibrils 26 or thread-like extensions of the sidewalls across the
second apertures 24. These fibrils 26 are created by incomplete
aperturing of the starting film. An unexpected advantage of the
fibrils 26 is that they provide the outer cover with additional
capability for preventing absorbent core materials from protruding
through the openings in the film.
[0020] This apertured formed film is placed on the tampon 10 so
that the second apertures 24 are generally adjacent the absorbent
core 12. An advantage of the apertured film cover is that it
minimizes the presence of the absorbent materials on the surface of
the tampon. The land region 16 has a projected land area which
results from projecting the land region 16 onto a plane
substantially parallel to it.
[0021] The size and number of the apertures in the film are chosen
to minimize the penetration of absorbent core materials through the
film. The presence of absorbent core materials on the surface of
the tampon both increases friction against the vaginal wall upon
insertion and contributes to desiccation of the vaginal wall during
use, leading to removal discomfort. The absence of absorbent core
materials on the surface of the tampon helps to maintain the ease
of insertion and removal.
[0022] The length of the sidewalls connecting the first and second
apertures may play a role in providing the tampon with improved
insertion characteristics. The presence of the sidewalls between
the first and second apertures imparts a generally
three-dimensional quality to the film. This three-dimensional
quality is in contrast to the generally two-dimensional quality of
reticulated films such as that described in U.S. Pat. No.
4,710,186, the disclosure of which is herein incorporated by
reference. Two-dimensional reticulated films more readily allow
portions of the absorbent materials of the absorbent core to
protrude through to the surface of the tampon.
[0023] The three-dimensional quality provided by the sidewalls
helps to separate the absorbent materials of the absorbent core
from the surface of the tampon. The longer the sidewalls, the
greater the separation of the absorbent core materials from the
tampon surface, and the less likely it is that the absorbent core
materials will protrude through the openings in the apertured film
to contact the vaginal tissues during insertion.
[0024] The optimum length of the sidewalls is dependent upon the
type of absorbent material which is used for the absorbent core.
Some types of absorbent materials may protrude more easily through
the openings in the apertured film, and thus longer sidewalls may
be required to prevent protrusion. It will be recognized by those
familiar with the manufacture of tampons that tampons are often
compressed during the manufacturing process. Such compression
causes the sidewalls of the apertured film to fold over. Such
folding, however, does not detract from the ability of the
sidewalls to prevent protrusion of the absorbent materials through
the openings in the apertured film.
[0025] FIG. 2 illustrates a side view of a prior art tampon 100
with a fiber cover 102. The surface 104 of the prior art tampon 100
has a "fuzzy" appearance caused both by absorbent core fibers
protruding through the fiber cover 102 and by loose fibers from the
cover 102.
[0026] FIG. 3 shows a side view of a tampon 10 of the invention
with an apertured film cover 14. The surface of the tampon 10 is
smooth with the fibers substantially all contained by the cover 14.
The apertured formed film cover 14 helps to hold the absorbent core
fibers away from the surface of the tampon 10. Since the apertured
formed film cover 14 does not comprise fibers, there are no loose
cover fibers to interfere with insertion and removal comfort.
[0027] This smoothness may be measured by average surface roughness
as measured by the Kawabata Surface Tester according to the method
described in the Examples. Preferably, the average surface
roughness is less than that of conventional fibrous tampon cover
material. More preferably, the average surface roughness is less
than about 3 microns.
[0028] The absorbent core of the tampon may comprise any absorbent
material, including but not limited to cellulosic fibers such as
rayon and cotton, other natural or synthetic absorbent fibers,
superabsorbent fibers, absorbent foams, absorbent gelling agents,
and the like. In a preferred embodiment, the absorbent core of the
tampon comprises a blend of rayon and cotton.
[0029] The apertured formed film of the invention may comprise any
polymeric film-forming material including but not limited to
polyethylene, polypropylene, other polyolefins, ethylene vinyl
acetate, polyesters, polystyrene, polyamides, polyethers,
copolymers of these, and blends of these. In a preferred
embodiment, the apertured formed film of the invention comprises a
blend of ethylene vinyl acetate and polypropylene. In another
preferred embodiment, the apertured formed film comprises a blend
of polypropylene and low density polyethylene.
[0030] The generally elongated absorbent core has a generally
elongated surface and two end surfaces. Preferably, the apertured
formed film substantially covers at least the generally elongated
surface of the absorbent core to form an outer cover on the tampon.
The outer cover is oriented and configured such that the second
apertures are adjacent to the absorbent core. One or both of the
ends of the absorbent core may also be covered, but this is not
necessary to obtain the insertion and removal advantages of the
invention.
[0031] The land region of the apertured formed film is chosen such
that it provides the outer body-contacting exterior of the tampon
with a gliding surface which allows for smooth and easy insertion
of the tampon into a body cavity. The smoothness of the surface
allows the tampon to slide easily over the vaginal tissues, thereby
reducing the frictional drag which may occur when fibrous or
absorbent or less smooth tampon surfaces rub along the sensitive
vaginal tissues. The projected land area, projected side wall area,
and open area of a given area of apertured formed film are equal to
unity. Of these three areas, the easiest to determine is the open
area. It has been found that apertured formed films with open area
of less than about 35% function effectively to provide this smooth
surface on tampons. However, apertured films with open area of as
little as 2% are also effective on such tampons.
[0032] Open area may be determined by using image analysis to
measure the relative percentages of apertured and unapertured, or
land, areas. Essentially image analysis converts an optical image
from a light microscope into an electronic signal suitable for
processing. An electronic beam scans the image, line-by-line. As
each line is scanned, an output signal changes according to
illumination. White areas produce a relatively high voltage and
black areas a relatively low voltage. An image of the apertured
formed film is produced and, in that image, the holes are white,
while the solid areas of thermoplastic material are at various
levels of gray. The more dense the solid area, the darker the gray
area produced. Each line of the image that is measured is divided
into sampling points or pixels. The following equipment can be used
to carry out the analysis described above: a Quantimet Q520 Image
Analyzer (with v. 5.02B software and Grey Store Option), sold by
LEICA/Cambridge Instruments Ltd., in conjunction with an Olympus
SZH Microscope with a transmitted light base, a plan 1.0.times.
objective, and a 2.50.times. eyepiece. The image can be produced
with a DAGE MTI CCD72 video camera.
[0033] A representative piece of each material to be analyzed is
placed on the microscope stage and sharply imaged on the video
screen at a microscope zoom setting of 10.times.. the open area is
determined from field measurements of representative areas. The
Quantimet program output reports mean value and standard deviation
for each sample.
[0034] In addition to open area, the apertured formed film of the
tampon of the invention is characterized by a distribution of the
distances of nearest neighbor apertures. Nearest neighbor distance
may be determined by a variety of means including the use of image
analysis for the calculation of the "nearest neighbor" in an array
of apertures. The nearest neighbor distance is the distance between
an aperture and the aperture which is its nearest neighbor in an
apertured formed film, measured from the centroid of the first
aperture tot he centroid of its nearest neighbor. This distance,
when plotted against the frequency of such distances, provides a
frequency distribution of nearest neighbors for the apertures in
the film. Such a nearest neighbor distribution may be observed in
FIGS. 4 (an apertured formed film according to the present
invention) and 5 (a thermobonded fibrous web). It can be noted from
FIG. 4 that the distribution for this apertured formed film sample
is binodal; that is, there is a first distribution of nearest
neighbor distances in the 0.5 to 1.1 mm range and a second
distribution in the 1.1 to 2.5 mm range. This binodal distribution
is attributed to the presence of fibrils across about 60% of the
second apertures in this sample of apertured formed film. In
contrast, as shown in FIG. 5, the nearest neighbor distribution for
a fibrous nonwoven cover similar to that formed on a commercially
available o.b..RTM. tampon shows a very narrow distribution of
nearest neighbor distances. Additionally, the nearest neighbor
distances for the fibrous cover are much smaller than for the film
cover. This illustrates that the apertures in the fibrous cover are
much closer together than the apertures in the film.
[0035] The apertured formed film may be applied as an outer cover
to an absorbent core to form a tampon by any of a number of known
methods. Preferred methods of applying the cover are disclosed in
U.S. Pat. No. 4,863,450 (Friese), in which a length of cover is
attached to one end of a length of absorbent material and the
assembly is rolled up into a cylinder such that the cover forms the
outside surface of the cylinder, and U.S. Pat. No. 5,004,467
(Hinzmann et al.), in which one end of an absorbent cylinder is
placed in the center of a rectangle of cover, and the cover is
folded up and around the sides of the cylinder. The contents of
these two patents are hereby incorporated herein by reference.
[0036] After the cover is applied to the absorbent core, the
covered core is radially compressed to form a tampon pledget. A
preferred compressed tampon and method for making it are described
in commonly assigned, co-pending U.S. Pat. application Ser. No.
07/596,456 (Friese et al.), the contents of which are hereby
incorporated herein by reference. The tampon of Friese et al. has a
generally cylindrical shape formed by multiple longitudinal,
relatively low-density ribs surrounding a more highly compressed
core. The term "generally elongated" as used herein is intended to
include the generally cylindrical tampon of Friese et al. as well
as other tampons with a generally elongated shape.
[0037] The compressed pledget may be inserted into a user's body
cavity with the user's fingers (digitally) or by means of an
applicator.
[0038] Apertured polymeric formed films are known and may be made
by a number of methods which are known to those in the art,
including hot air aperturing and water aperturing. A preferred
apertured formed film for this invention is made using an apparatus
as described in U.S. Pat. No. 5,567,376, the contents of which are
hereby incorporated herein by reference. FIG. 6 illustrates a
method of making an embodiment of an apertured film for use in this
invention. A continuous starting film 200 is unwound from an unwind
station 210 and supported on a three-dimensional apertured forming
member 220. Situated above the starting film 200 is a manifold 230
for applying multiple fine streams of hot water to the upper
surface of the starting film 200 as the film, supported on the
forming member 220, passes under the manifold 230. The water may be
applied at varying pressures. High pressures (i.e., 900 pounds per
square inch) or low pressures (i.e., 165 pounds per square inch)
may be used, as may combinations of high and low pressures.
Disposed beneath the forming member 220 is a vacuum manifold 240
for removing water which is directed onto the upper surface of the
starting film 200 as it passes under the manifold 230.
[0039] The pressurized streams of hot water cause the film to
conform to the topography of the apertured forming member 220 and
to rupture in the areas where the film overlies the apertures in
the forming member 220. The resulting apertured formed film has a
top surface corresponding to the surface contacted by the water
streams, and a bottom surface corresponding to the surface
supported by the forming member 220. The apertured film is then
passed through one pair or dewatering rolls, 250A and 250B, and one
pair of backing rolls, 260 and 270, to remove excess water and to
dry the film. Surfactant is then applied to the top surface of the
apertured film, the film is slit, e.g., by a cutting knife 280,
into appropriate widths for tampon converting lines, and the narrow
widths of film are wound onto standard cores 290.
[0040] The narrow widths of apertured formed film are then cut into
strips of predetermined lengths. The cut edge of each strip of the
apertured film is heat-welded to the outside of the rear end of a
section of a cotton/rayon nonwoven ribbon. The blend of cotton and
rayon in the nonwoven ribbon may range from 100% cotton and 0%
rayon to 0% cotton and 100% rayon. Preferably, the blend of cotton
to rayon ranges from 25:75 to 0:100. The nonwoven ribbon is
provided with a withdrawal cord and rolled up on itself to form a
tampon blank so that the apertured film length extends over the
circumference of the tampon blank with the top surface of the
apertured film facing away from the nonwoven ribbon. The free end
of the apertured film length is heat-sealed onto the outer
apertured film-covered surface of the blank. The blank is
subsequently radially compressed to produce the final form of the
tampon.
EXAMPLES 1A, B, C, D
[0041] Tampons 1A and 1C are made by applying the apertured film
cover according to the method above. Tampons 1B and 1D are made by
first rolling up a section of a cotton/rayon nonwoven ribbon to
form a generally cylindrical tampon blank. One end of the blank is
placed on the center of a length of apertured film. The apertured
film is folded up and around the sides, or generally cylindrical
surface, of the tampon blank. The covered blank is then radially
compressed to form a tampon.
[0042] Tampons 1A, 1B, 1C, and 1D are tested for absorbency by a
standard Syngina test, as described in the Federal Register, Part
III, Department of Health and Human Services, Food and Drug
Administration (21 CFR Part 801, pp. 37263-4, Sep. 23, 1988). It
can be seen from Table 1 below that tampons made with films of
small open area (high land area) demonstrate Syngina capacities
which are comparable with tampons made with higher open area (lower
land area) films and fibrous covers.
1 TABLE 1 Apertured Film Syngina Open Area Capacity Product (%) (g)
Tampon 1A with apertured 2.3 9.2 film cover Tampon 1B with
apertured 3.0 9.5 film cover Tampon 1C with apertured 3.6 9.3 film
cover Tampon 1D with apertured 22.7 9.7 film cover Commercial o.b.
.RTM. with -- 9.2 fibrous cover
EXAMPLE 2
[0043] A comparison was made of the perceived insertion and removal
comfort of two control products, (1) a super absorbency commercial
digital tampon with a fiber cover (o.b..RTM. Brand), and (2) a
digital tampon made with a two-dimensional reticulated film, such
as that described in U.S. Pat. No. 4,710,186, and an experimental
tampon made by substituting an apertured film cover with an open
area of 3% for the fiber cover on a super absorbency commercial
o.b..RTM. tampon. The test tampon (Example 2) was made according to
the same method used to made Tampons 1A and 1C above. Fifty-five
panelists were each given one each of the control product and the
test tampon. Each participant was instructed to insert the tampons
digitally during nonmenstrual days only to simulate light flow
days. Each tampon was to be worn for 3 to 4 hours before being
removed, and there was to be a minimum of 20 hours between the
testing of each tampon. The panelists completed questionnaires
immediately after the insertion process of each tampon and then
again immediately after the withdrawal process of each tampon. The
panelists were asked to rate each tampon from 0, extreme negative,
to 10, extreme positive, on their perceptions of various attributes
of the tampons. The results of the test are shown below in Table
2.
2TABLE 2 Reticulated o.b. .RTM. Super Film of U.S. Example 2
Attribute absorbency Pat. No. 4,710,186 Tampon Overall insertion
6.9* 7.4 7.7 performance Easy to position 7.1* 7.7 7.9 for
insertion Comfortable 7.1* 7.6* 8.1 during insertion Easy glide
6.4* 7.3 7.7 Overall removal 6.7* 7.2 7.4 *Indicates that the
number shown is significantly less at a 95% confidence level as
measured by the Paired T-test.
[0044] It can be seen from the results in Table 2 that the tampon
with the apertured formed film cover (Example 2 tampon) was rated
higher than the commercial tampon for overall insertion, ease and
comfort of insertion, easy glide, and overall removal.
[0045] These cover materials were also tested for Coefficient of
Friction on polished steel and surface roughness. The surface
roughness was measured using the Kawabata Surface Tester KES-FB-4,
available from Kato Tekko (Kyoto, Japan).
[0046] The Kawabata Surface Tester allows the measurement of
surface roughness of films and nonwoven fabrics. In performing this
test, the mean deviation of surface roughness, SMD, is measured
over a distance of 2 cm. The contactor for measurement of surface
roughness is a steel piano wire (0.5 mm diameter, 5 mm length)
placed on the material surface with a contact force of 10 gf (gram
force). The contactor is specially designed to simulate the human
finger surface. The specimen is moved between a 2 cm interval both
backwards and forwards at a constant velocity of 0.1 cm/sec on a
horizontal smooth steel plate. The tension of the specimen is kept
constant at 20 gf/cm and the contactor stays in place during the
measurement. The electrical signal related to the vertical
displacement of the piano wire is then translated into a digital
readout.
[0047] The results of the Kawabata Surface Tester and Coefficient
of Friction on Steel are shown below in Table 3.
3TABLE 3 Surface Surf. Rough. Coefficient Roughness Std. Dev. of
Product (microns) (microns) Friction Reticulated Film of 3.5 0.24
0.11 U.S. Pat. No. 4,710,186 Fibrous cover of 3.2 0.20 0.16
Commercial o.b. .RTM. Apertured Formed 1.5 0.87 0.22 Film as in Ex.
2
[0048] It can be seen from the surface roughness test results that
the three-dimensional apertured formed film of the invention has a
lower average surface roughness than either the fibrous cover from
a commercial o.b..RTM. tampon or a two-dimensional reticulated
film. In the Kawabata Surface Roughness Test, lower measurements
indicate lower surface roughness.
[0049] However, as Table 3 shows, the lower surface roughness does
not result in a lower coefficient of friction. The apertured formed
film has a higher coefficient of friction on polished steel than
either the reticulated film or the fibrous cover. Surprisingly, a
tampon surface that provides greater frictional drag demonstrates
greater comfort upon actual insertion into and removal from a
woman's vagina than a tampon having a cover with less frictional
drag.
[0050] The specification and examples above are presented to aid in
the complete and non-limiting understanding of the invention
disclosed herein. Since many variations and embodiments of the
invention can be made without departing from its spirit and scope,
the invention resides in the claims hereinafter appended.
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