Note: Descriptions are shown in the official language in which they were submitted.
1 Y
PATENT
DISPOSABLE MENSTRUAL PANTY
Field of the Invention
This present invention relates to undergarments in general, and
more specifically to women's disposable undergarments having a fluid
repellent region and an absorbent layer to be used with a woman's
normal feminine care protection during her menstrual period.
Background of the Invention
Regular undergarments in current use are made of cotton and/or
synthetic materials. The cotton and synthetic panties typically do
not offer barrier protection. Often the synthetic panties have a
cotton lined crotch to absorb vaginal discharges or perspiration.
The absorbent/barrier properties of regular undergarments are minimal
such that any vaginal discharge and/or heavy perspiration may strike
through onto outer clothing {i.e., penetration of liquid from the
interior to the exterior of the panty.)
Panty liners and feminine care sanitary napkins or pads used
with regular undergarments have polyethylene backings that provide
some barrier properties needed to prevent liquid strike through.
However, if the vaginal discharge extends to the sides or the ends of
the pads it can leak onto the undergarment. This leakage can stain
the undergarment. Depending upon the amount of leakage, liquid may
strike through or go around the undergarment to stain outer clothing
and/or bedding. Women with heavy periods often use one or more maxi
pads, double pads and/or tampons alone, or in combination, and change
these pads and tampons frequently to prevent embarrassing, messy
leakage and/or staining of outer clothing. In some cases, during
their heaviest flow days, women will restrict their activities and
stay home.
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A majority of women experience some leakage of menses from their
pads to their undergarments. This varies from being limited to a
small number of pads leaking onto only the undergarment during light
flow to leakage onto the wearer's outer clothing on almost half the
pads worn during heavy flow. Normally this leakage occurs at the
side of the product, although end leakage is also a problem.
Placement of maxi pads and overnight pads in the crotch of regular
undergarments shows that, at best, the pads lay on the leg elastic
IO and, at worst, overhang the leg elastics. This causes side leakage
onto the undergarment and possibly onto outer clothing. Typical
leakage from the pads is caused by poor fit of the pad to the body,
improper positioning of the pad by the user and lack of absorbency.
Leakage from the undergarment onto the outer clothing is due to
incompatibility between the pad width and the panty crotch width and
lack of barrier properties in the panty material around the edge
portion of the pad.
Summary Of The Invention
Briefly, this invention describes a three dimensional,
disposable, discrete panty with fully elasticized leg and waist
openings that is circumferentially stretchable about the hip and
stomach regions and which provides back-up leakage protection to
feminine care products. It is particularly useful during the
wearer's menstrual period, normally occurring in non-pregnant women
about every four weeks, from menarche to menopause.
The protection benefit is obtained by providing a flexible
secondary absorbent associated with the crotch of the undergarment
which holds the primary absorbent in proper location for vaginal
discharge (menses). The secondary absorbent extends from the crotch
into the body of the undergarment front and back and may extend over
the leg elastics. This provides an undergarment which is capable of
trapping and absorbing the leakage from the pad and preventing liquid
strike through onto outer clothing and bed linen.
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Brief Description Of The Drawinas
The present invention will be more fully understood and further
advantages will become apparent when reference is made to the
following detailed description of the invention and the drawings, in
which:
Fig. 1 is a top plan view of a panty article of the present invention
in a preassembled flat configuration;
Fig. 2 is a perspective view of a full-sized, disposable menstrual
panty of the present invention.
Fig. 3 is a sectioned view taken along view lines 3-3 of Fig. 1 and
illustrating the outer cover, liner and elastics.
Fig. 4 is a sectioned view taken along view lines 4-4 of Fig. 1 and
illustrating the absorbent layer, barrier and outer cover.
Detailed Description of the Preferred Embodiments
The following detailed description is made in the context of an
article including a disposable panty for holding a sanitary pad in
place during use. It is readily apparent, however, that the present
invention can be employed with other disposable articles, such as
feminine tampons, incontinent garments and the like.
The disposable panty of FIG.1 illustrates the preferred
embodiment of the present invention in a flat configuration prior to
assembly. In FIG. 1, a panty 12 is shown having an outer cover 13
which includes a front body portion 14, a back body portion 15, a
front waist portion 16, a back waist portion 17, a crotch portion 18,
waist liner 26 (not shown), leg liner 38 (not shown) and body
liner 80 (not shown).
The outer cover 13 is compliant and soft feeling to the wearer.
The outer cover 13 may be liquid pervious, permitting liquids to
readily penetrate into its thickness, or impervious, resistent to the
penetration of liquids into its thickness. A suitable outer cover 13
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may be manufactured from a wide range of materials, such as natural
fibers (e. g., wood or cotton fibers), synthetic fibers (e. g.,
polyester or polypropylene fibers) or from a combination of natural
and synthetic fibers or reticulated foams and apertured plastic
films.
There are a number of manufacturing techniques which may be used
to manufacture the outer cover 13. For example, the outer cover 13
may be woven, nonwoven, such as spunbonded, carded, or the like. A
suitable outer cover 13 is carded, and thermally bonded by means well
known to those skilled in the fabric art. Alternatively, the outer
cover is a spunbond. Ideally, the outer cover is a spunbond
polypropylene nonwoven with a wireweave bond pattern having a grab
tensile of 19 pounds as measured by ASTM D1682 and D1776, a Taber 40
cycle abrasion rating of 3.0 as measured by ASTM D1175 and Handle-0-
Meter MD value of 6.6 grams and CD value of 4.4 grams using TAPPI
method T402. Suitably, the spunbond material is available from
Kimberly-Clark Corporation, located in Roswell, GA. The outer
cover l3 has a weight from about 0.3 oz. per square yard (osy) to
about 2.0 osy and alternatively about 0.7 osy. Preferably, the
outer cover of the undergarment has a printed pattern, is colored or
is decoratively embossed.
Referring to FIGS. 1, 2 and 3, an edge 60 of front body
portion 14 is assembled with an edge 62 of the back body portion 15
to form a seal 64. Similarly, an edge 66 of the front body
portion 14 is assembled with an edge 68 of the back body portion 15
to form a seal 70. The waist portions 16 and 17, when assembled form
a waist opening 20 for putting on and taking off the panty 12. The
waist opening 20 is surrounded at least in part by a waist
elastic 22. The waist elastic 22 is stretched and attached to the
waist portion 16. The waist elastic 22 is released after attachment
to produce waist folds or pleats 24 to allow expansion of the waist
opening 20 so that the panty 12 can fit various sized women. Because
users of this invention generally prefer a brief style panty, the
waist portion 16 of the panty 12 preferably comes to the navel and
even around the wearer's waist. Having the panty 12 at this height
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21~~~~~
and then drawing in the waist portion 16 with the waist elastic 22
provides a snug fit. Alternative panty styles include bikini (e. g.
regular leg cut and french leg cut) and hipster (e.g. regular leg cut
or french leg cut).
Referring again to FIGS. 1 and 2, the front body portion 14 and
the back body portion 15 together with the crotch portion 18 forms
leg openings 28 and 30, respectively, which are generally circular or
oval in shape. The leg openings 28 and 30 are each surrounded at
least in part by leg elastics 32 and 34, respectively. The leg
elastics 32 and 34 are stretched and attached to the front and back
body portions 14 and 15 and the crotch portion 18. The elastics are
released after attachment to produce leg folds or pleats 36 to allow
expansion of the leg openings 28 and 30 to fit various sized legs.
The front body portion 14 is usually divided into a front upper
portion 40 and a front lower portion 42. Similarly, the back body
portion 15 is divided into a back upper portion 41 and a back lower
portion 43. The upper portions 40 and 41 are preferably designed to
include body elastics 44 which are capable of stretching to allow the
wearer to put on the panty 12 and then readily resume the body
elastic's normal contracted form. This ensures a close or snug fit
to different body and size forms. A number of body elastics 44 are
positioned on both the front and the back portions 40 and 41,
respectively, at positions between the waist opening 20 and the leg
openings 28 and 30, so that the panty 12 fits the wearer better,
particularly around the body. The lower body portions 42 and 43 do
not necessarily require elastics. If the outer cover incorporates
the body elastic, the basis weight of the outer cover and body
elastic laminate may be as high as 5 osy.
In reference to the crotch portion 18 of FIG. 1, the functional
total capacity of normal pads worn during the menstrual cycle ranges
from about 12 grams to about 63 grams. More typically, the capacity
of the pads is above 20 grams. The marketing names associated with
such pads include "thin maxi", "maxi", "thick maxi" and "super
maxi". These will be referred to as maxi pads. The entire absorbent
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core normally contained in a maxi pad and which is used during medium
to high menstrual flow periods in the panty 12 is the "primary"
absorbent 45. The absorbent which is associated with the crotch
portion of the current invention is the "secondary" absorbent.
The crotch portion 18 of the panty 12 consists of an absorbent
barrier composite 46. The absorbent barrier composite 46 further
consists of a liquid barrier 48 and a secondary absorbent 50.
Preferably, the thickness of the crotch portion 18 is less than about
4 mm. The thickness is measured on a 4 inch (102 mm) square sample
(leg elastics removed) with a Mitutoyo Digamatic Indicator using a 3
inch (76 mm) diameter acrylic platen and assembly to produce a
pressure of 0.05 psi. The liquid barrier 48 is needed to prevent
liquid strike through on the outer clothing when leakage occurs on
the panty 12. The liquid barrier 48 is located on the inside of the
crotch portion 18 and consists of a liquid impervious film such as
polyethylene. Use of only the film would be hot and uncomfortable,
would not be durable enough to withstand changing of pads and would
smear any menses which leaked off of the primary absorbent 45. Any
film crotch material in the prior art that is elastic is nominally
undesirable for the attachment of a pad since the stretch could
detach the pad. Therefore, it is desirable to associate the
secondary absorbent 50 with a liquid barrier 48 which is nonelastic.
The secondary absorbent 50 should have a liquid capacity great
enough to absorb leakage of menses from the primary absorbent 45.
The secondary absorbent 50 should preferably have a capacity
(described below) and a thickness substantially less than that of the
primary absorbent 45, thus providing a nonbulky and flexible fit.
The capacity of the secondary absorbent 50 should have a total
capacity of about one-half of the primary absorbent 45. Preferably,
the secondary absorbent 50 should have a total capacity of at least
about 3 grams and not more than 6 grams. More preferably, the total
capacity of the secondary absorbent 50 should be from about 4 grams
to about 6 grams.
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21 ~5~~
The total capacity of the primary absorbent 45 and the secondary
absorbent 50 are determined as follows. Any panty adhesive release
paper is removed from the pad to be tested. The total capacity of
the primary absorbent 45 is determined using the entire napkin minus
any release paper. The total capacity of the secondary absorbent 50
is determined using the absorbent barrier composite 46 of the panty
12 and the outer cover 13. The specimen is weighed to the nearest
0.1 gram and acclimated at standard relative humidity and temperature
for two hours. The specimen is then submerged in a beaker of sterile
saline (0.9% sodium chloride solution obtainable from the Baxter
Travenol Company of Deerfield, Illinois), such that the specimen is
totally submerged and is not bent or otherwise twisted or folded.
The specimen is submerged for 10 minutes. The specimen is removed
from the saline and suspended for two minutes in a vertical position
to allow the saline to drain out of the specimen. The specimen is
then placed body facing surface down onto an absorbent blotter, sueh
as filter paper #631 available from the Filtration Science Corp,
Eaton-Dikmena Division of Mount Holly Springs, Pennsylvania. A
uniform 17.6 grams per square centimeter load is placed over the
specimen to squeeze excess liquid out of the specimen. The absorbent
blotter is replaced every 30 seconds until the amount of liquid
transferred to the absorbent blotter is less than 0.5 grams in a 30
second period. The specimen is then weighed to the nearest 0.1 gram
and the dry weight of the specimen is subtracted from the final wet
weight. The difference in grams is the total capacity of the
specimen.
In construction of the absorbent barrier composite 46, the
liquid barrier 48 should retard the movement of the liquid through
the absorbent barrier composite 46 by making the barrier liquid
resistant to penetration normally encountered under wearing
conditions. The composite may be rendered liquid impermeable by any
method well known in the art such as coating the secondary absorbent
50 or by securing a separate liquid impermeable material to the
secondary absorbent 50. Alternatively, the liquid barrier 48
consists of a liquid impervious film or foam which is pervious to
water vapor under normal wearing conditions. More preferred, the
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liquid barrier 48 has a water vapor transmission rate of at least
about 3500 grams/m2/day measured by ASTM E96-92. One example of a
suitable film is a 39.4 grams per square meter microporous film
produced by Mitsui and sold by Consolidated Thermoplastics (CT) under
the tradename of ESPOIR~ N-TAF-CT.
The secondary absorbent 50 may be any construction which is
generally compressible, conformable, non-irritating to the wearer's
skin, capable of absorbing and retaining menstrual fluid.
Optionally, the secondary absorbent 50 has first and second opposed
faces and includes an absorbent rich layer 51 and a support layer 53.
The absorbent rich layer 51 may be manufactured in a wide variety of
sizes and shapes (e.g., rectangular, hour-glass, etc. ) and from a
wide variety of liquid absorbent materials, such as fiberized wood
pulp. Examples of other suitable absorbent materials include creped
cellulose wadding, absorbent foams, absorbent sponges, superabsorbent
polymers, or any equivalent material or combination materials-. The
support layer 53 may be any construction which is generally resistent
to deterioration by liquids while being conformable, non-noisy and
capable of holding the absorbent rich layer 51 in place.
Alternatively, the absorbent rich layer 51 consists of a 70 gsm
1:1 blend of northern hardwood pulp and southern softwood pulp. The
support layer 53 can be a 14 gsm spunbond. The pulp layer is
hydroentangled through the spunbond and then microcreped. The liquid
barrier 48 and the secondary absorbent 50 are bonded together using
an adhesive 72 add-on of 3 to 7 gsm. Optionally, the absorbent rich
layer 51 is bonded to the barrier of the absorbent barrier
composite 46. This arrangement permits improved attachment, removal
and reattachment of the primary absorbent 45 to the panty 12. The
liquid barrier 48 is bonded to the outer cover 13 on the inside of
the panty with an adhesive 74 add-on of 5 to 10 gsm. The liquid
barrier 48 may be an adhesive film which bonds the secondary
absorbent 50 to the outer cover 13. A suitable adhesive for both
applications includes, for example, National Starch NS 34-5561 hot
melt adhesive which is available from National Starch and Chemical
Company located in Bridgewater, NJ.
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The width of the crotch portion 18 between the leg elastics 32
and 34 should be wide enough to lay the primary absorbent 45 between
the edges without having the primary absorbent 45 obstruct the leg
elastics. This allows the leg elastics 32 and 34 to contract and
draw up the sides of the crotch to accommodate the depth of the
primary absorbent 45 being used and give surface area within the
crotch portion 18 to contain leakage from the primary absorbent 45.
The minimum width of the crotch portion 18 should not be so wide
as to seem bulky or uncomfortable, but a suitable width is at least
about 2.75 inches (70 mm) between the leg elastics. The minimum
width is advantageous from about 3 inches (76 mm) to about 3.5 inches
(89 mm). Optionally, the width is about 3 inches (76 mm).
Preferably, the leg elastics 32 and 34 are from about 0.375 inch (10
mm) to about 0.625 inch (16 mm) wide. More preferably, the width is
about 0.5 inch (6 Win). Preferably, ruffle material on the edge of
the leg openings 28 and 30 outside the leg elastics 32 and 34 is less
than about 0.25 inch (13 Win). More preferably, the ruffle material
is less than about 0.125 inch (3 mm). It is most desirable to
eliminate the ruffle material from the edge of the leg openings 28
and 30. The overall width of the crotch portion 18 includes the
width between the leg elastics 32 and 34, the width of the leg
elastics 32 and 34 and the ruffle material outside the leg
elastics 32 and 34 to the edge of the leg openings 28 and 30.
Preferably, the overall width of the crotch portion 18 should be at
least about 4 inches (102 nmi). The width of the absorbent barrier
composite 46 is sized in relation to the width of the crotch
portion 18. Preferably, the width of the composite 46 is at least
the width of the crotch portion 18 between the leg elastics 32
and 34. More preferably, the width is equivalent to the width of the
crotch portion 18.
The overall length of the absorbent barrier composite 46 should
be adequate to extend beyond the ends of the maxi pads to help
prevent liquid strike through at these points when sleeping or
sitting. This overall length is at least about 15 inches (381 mm)
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~.~~1~,~'h'
thus extending beyond the crotch portion 18 along the longitudinal
centerline A-A of the panty 12. Alternatively, the length should be
in the range of about 15 inches (381 mm)to about 19 inches (483 mm).
Optionally, the length of the composite 46 is about 17 inches(432
mm).
The width of the absorbent barrier composite 46 beyond the
crotch portion 18 should be at least as wide as the width of the
crotch portion 18. The width of the absorbent barrier composite 46
could be narrowed beyond the crotch portion 18 but may compromise the
leakage containment. More preferably, the width is from about 5
inches (127 mm) to about 12 inches (305 mm), alternatively from about
5.5 inches (140 mm) to about 7.5 inches (191 mm). Optionally, the
width is about 6.5 inches (165 mm).
The present invention contemplates various shapes of the
composite 46. One preferred composite has a non-rectangular shape
with rounded ends which provides extensive coverage in the seat of
the finished panty 12. Another preferred absorbent barrier
composite 46 embodiment is rectangular in shape with rounded ends.
The essentially rectangular-shaped absorbent barrier composite 46 is
more preferred since it can be squared off at the ends to provide a
smoother appearance in the back of the panty 12. Line 76 may be
embossed or printed on the inner surface of the crotch portion 18 to
aid in placement of the primary absorbent 45 by the wearer.
Referring to FIG. 3, the waist elastic 22 is shown covered with
a waist liner 26. Referring to FIGS. 3 and 4, the leg elastics 32
and 34 are shown covered by the absorbent barrier composite 46 and a
leg liner 38. Referring to FIG. 3, the body elastic 44 is shown
covered with a body liner 80. The liner consists of a nonwoven or
other soft material for contacting the wearer's skin.
The position and the shape of the leg openings 28 and 30 are
important to avoid tightness in the crotch and groin area of the
wearer, to obtain adequate buttocks coverage, and to prevent the
panty 12 from tilting forward, i.e. tilting such that the front waist
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edge dips lower in relationship to the back waist edge. Fig. 1
illustrates the most preferred design for leg fit and buttocks
coverage. The shape of the curve across the top of the leg may be
considered. If the curve is too deep, the panty l2 will shift
downward and backward resulting in a short front waist, increased
back length and bagginess in the seat of the panty. This causes the
panty 12 to appear tilted when worn as evidenced by an unevenness
around the waist of the wearer.
The leg openings 28 and 30 are important to the correct
functioning of the panty 12. With the panty 12 laid out flat as in
FIG. 1, the majority of the back half of the leg opening preferably
forms a straight line. More preferably, the back edge of the leg
opening is straight for a length, e, of at least about 70y. of the
length of the entire back half. The straight section a of the back
half of the leg opening should form an acute angle with the
longitudinal centerline, A-A, of the panty 12. More preferably, the
line, e, forms an angle, a, with the centerline A-A of the panty 12
of between about 50' and 65' and most preferably about 60'. The
majority of the edge of front half of the leg opening including
lengths ~ and f also preferably forms a straight line. More
preferably, the lengths of edge a and ~ of the leg opening is
straight for at least about 70~. of the length of the front half. The
straight section ~ of the front half of the leg opening should form
an angle with the centerline of the panty 12 of between about 75' and
110' and most preferably about 90'.
Likewise, the shape of the arc at the inner groin area is
important. If the arc is too shallow, tightness may be experienced
at the inner groin area. The preferred narrow crotch width reduces
coverage of the buttocks. To compensate for such reduction, the back
curve is preferably adjusted downward. The arc between the crotch
edge of the leg opening and the back edge of the leg opening should
si;art slightly in front of centerline B-B of the panty 12, see
FIG. 1. This allows the leg elastic to be positioned below the lower
edge of the buttocks and helps prevent the panty 12 from riding up
when walking. This means that the straight portion ~ of the inner
edge of the leg opening is entirely forward of the panty 12
centerline B-B.
The waist, leg and body elastics 22, 32, 34 and 44,
respectively, are attached to the panty 12 on the outer cover 13 in
generally a stretched state by means known in the art, such as
ultrasonic bonded, heat/pressure bonded or adhesively bonded.
Materials suitable for elastics include a wide variety including but
not limited to elastic strands, yarn rubber, flat rubber, elastic
tape, film-type rubber, polyurethane and elastomeric, tape-like
elastomeric or foam polyurethane or formed elastic scrim. Each
elastic may be unitary, multipart or composite in construction.
The waist elastic 22 is about 0.5 inch (13 mrn) wide. The
elastic may comprise threads, ribbons, a film or composite. The
threads or ribbons may be multiple and may be applied as a composite.
Preferably, the waist elastic is threads, more preferably four
threads are used as the elastic and the threads are spaced about
0.125 inch (3 mm) apart. The threads may be made of any suitable
elastomeric material. One suitable material is spandex such as
Lycra~ threads available from Dupont located in Wilmington, Delaware.
Suitable waist elastics include threads having a total decitex
(g/10000m) of about 3760 for 0.5 inch (13 mm) wide elastic.
Adhesive 74 is used to bond the elastic to the outer cover 13 and the
waist liner 26. A suitable adhesive includes, for example, Findley
H2096 hot melt adhesive which is available from Findley Adhesives
located in Milwaukee, WI.
The leg elastics 32 and 34 are about 0.5 inch (13 mm) wide.
The elastic may comprise threads, ribbons, a film or composite. The
threads or ribbons may be multiple and may be applied as a composite.
The leg elastics may be threads, preferably numbering four threads
which are spaced about 0.125 inch (3 mm) apart. The threads may be
made of any suitable elastomeric material. One suitable material is
spandex such as Lycra~ threads available from Dupont located in
Wilmington, Delaware. Suitable leg elastics include threads having a
total decitex (g/10000m) of about 3760 for a 0.5 inch (13 mm) wide
elastic. Adhesive 74 is used to bond the elastic to the outer
cover 13 and to the leg liner 38.
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CA 02105455 2004-02-23
To provide a snug leg fit and to draw up the sides of the crotch
portion 18 to form the primary absorbent cradle, the leg elastics 32
and 34 are applied to the outer cover 13 under an elongation of about
250%. Preferably, during the application of the elastics, the
elastics 32 and 34 are segmented into multiple segments, each segment
being elongated to a different degree and applied to the outer
cover 13. In the case of two segments, the front segment is
elongated less than the back segment. In the case of three segments,
the front and crotch segments are elongated less than the back
section. Preferably, the front and crotch segments are elongated to
about 150f. and the back segment is elongated to about 250%. The
segmenting and differing tensions allow easier pad attachment, less
tightness in the groin area, and less bunching of the crotch
portion 18 caused by high leg elastic retraction. The back leg
elastic is under higher elongation to help keep the seat of the panty
from creeping up with movement during use.
The body elastics 44 circumferentially surrounding the body
portions 14 and 15 of the panty 12 act in a circumferential
direction, i.e. about a circumference of the panty, independently
to conform to the contours of various bod t
y ypes and builds. This
provides a smooth, snug, and comfortable fit within a given hip
size range. Using higher elongation, closer spacing, and higher
cross-sectional area in the waist elastic 22 than in the body
elastics 44, the panty 12 takes on a rounded shape and provides
good waist fit across the waist to hip ratios encountered.
Preferably, in the front body portion the body elastics 44
adjoin both the waist elastic 22 and leg elastics 32 and 34. In a
panty 12 which is sized as 7/8, the body elastics 44 are about 6.25
inches (159 mm) wide in the front and about 6.75 inches (171 mm) wide
in the back. The body elastics 44 are preferably spaced about 0.25
inch (6 mm) apart.
The absorbent barrier composite 46 which extends up the front
and/or back body portions toward the waist portion is conformed to
the wearer's body by the body elastic 44. The transition from the
front and back lower portions to the front and back upper portions is
thus smoothed.
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- . CA 02105455 2004-02-23
The waist elastic 22 is desirably under a greater tension per
unit width than the body elastics 44 in the upper body portion 40 to
provide the snug waist fit over the range of waist to hip ratios of
the various body shapes. In the preferred embodiment, the tension on
the waist elastic 22 is coordinated with the tension of the body
elastics 44, the tension being caused by retroactive forces of the
elastics) about a circumference of the panty, to form a snug fit
about the waist opening while providing a smooth transition from
the upper body portion 40 to the waist portion 16.
In the front and back body portions 14 and 15, the leg, waist
and /or body liners may be expanded to cover the interior of the body
portions 14 and 15. The leg, waist and/or body liners may exclude
the center crotch portion 18 which is covered by the application of
the absorbent barrier composite 46. In the body portions where the
absorbent barrier composite overlaps the liner, the composite is
applied on top of any liner present so as to contact the wearer.
An acceptable range for the waist elastic tension is from about
380 grams to about 1000 grams. More preferably, the tension at the
waist is from about 600 grams to about 750 grams. The preferred leg
elastic tension is from about 375 grams to about 1000 grams. More
preferably, the tension at the leg is from about 450 grams to about
700 grams. The preferred hip elastic tension is from about 500 grams
to about 850 grams. More preferably, the tension at the hip is from
about 650 grams to about 750 grams. The waist and leg tensions are
determined as follows. The appropriate gauge rod distance is
selected from the Table 1 for a given panty size and desired location
measurement. This rod distance is the distance between the top of
the upper peg and the bottom of the lower peg on the Chatillon DFG-2
Tensile Tester.
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,~!r ,.
TABLE 1
Gauge Rod Distance
Pant Size Waist Leg
5/6 354 mm 278 mm
7/8 392 mm 306 mm
9/10 468 mm 345 mm
Measurements are recorded on the tester in kilograms, the HOLD/NORM
switch is set at "NORM", the T/C switch is set at "T" (tension). The
samples are conditioned and the testing is conducted in a standard
laboratory atmosphere of a temperature of 23 ~ 2'C and a relative
humidity of 50 ~ 59~ RH.
For determination of the waist tension, the edge along the
bonded seam of the panty 12 is placed over the upper peg of the
tester. The panty 12 is allowed to hang freely from the upper peg
and the weight of the specimen is determined.
The lower block is lifted upwards and the opposing waist edge
along the bonded seam is placed over the peg of the lower block. The
block is lowered until the magnet of the tensile tester locks into
place. The tester is activated and timed for two minutes. At two
minutes, the tension displayed on the gauge is recorded. The tension
in kilograms is converted to grams and the panty 12 is removed.
For determination of leg tension, the edge along the bonded seam
near the crotch fold is placed over the upper peg. The panty 12 is
allowed to hang freely from the upper peg and the weight of the
specimen is determined.
The lower block is.lifted upwards and the bonded seam along the
opposing leg opening edge is placed over the peg of the lower block.
The block is lowered until the magnet of the tensile tester
locks into place. The tester is activated and timed for two minutes.
At two minutes, the tension displayed on the gauge is recorded. The
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tension in kilograms is converted to grams and the panty 12 is
removed. This measurement represents the right leg tension. The
test is repeated for the left leg tension.
For determination of hip tension, the top and bottom side seams
of the body portion of the panty 12 are placed in the upper and lower
8 inch wide jaws of an Instron Model 1122 equipped with a Sintech
software system and the Interactive Materials Analysis Program
(IMAP).
The tension program stretches the elastic body portion at a rate
of 500 mm/minute until 1000 grams is reached. The crosshead then
returns to the starting position and repeats a second cycle. The
stress-strain graph can be plotted and tension data points printed at
50, 60, 70, 80, 90% of the full stretch (defined as length at 1000
grams) for first and second load and unload cycles. The tensions
were taken from the second cycle unload values at about 85%.
The side seams 64 and 70 may be made on the inside or outside of
the panty 12 or formed flat against the panty 12 to give a more
finished look to the panty 12 and to prevent the seams 64 and 70 from
showing through clothing. Optionally, the lateral edges 60, 62, 66
and 68 of the front and back body portions are not overlapped but are
formed flat and extend out laterally. The side seams 64 and 70
should be minimal in width while providing sufficient strength to be
pulled up and down many times over a 24 hour wear period.
The side seams 64 and 70, respectively, of the outer cover 13
are sealed by means known in the art, such as ultrasonic bonding,
stitching heat/pressure bonding or adhesive bonding. The maximum
seam strength attainable is dependent upon materials used, bond
pattern, bond width, and process settings of dwell time, power, and
pressure. Suitable side seams typically utilize ultrasonic bonding
to achieve a seam strength of at least 5 kg.
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The seams 64 and 70 may have an unbonded portion outboard of the
bonded area to provide for a soft edge to the seam. This unbonded
portion can ranged from 2 to 3 mm in width. Alternatively, the
entire seam width (bonded portion plus unbonded portion) may be less
than about 0.25 inch (6 mm). If the seam is trimmed or cut close to
the outer edge of the bond area, a sharp edge is produced along the
seam edge which can catch on clothes or be irritating to the wearer's
skin.
The panty 12 was compared to panties constructed of cotton and
panties having a barrier but no secondary absorbent 50. Seventeen
women were retained for this comparison. Each woman wore a selected
maxi pad with each panty type until the pad leaked onto that panty
type. Loose-fitting cotton shorts were worn by each woman over the
panty which could be worn under their normal loose-fitting clothing.
At the end of each test, the pad, panty and cotton shorts were
collected. The pad, panty and shorts were photographed. The results
of the comparison found that cotton panties had leakage to outer
garments in 35.39 of the women, panties with barriers but no
secondary absorbent 50 had leakage in 41.29 of the women and the
panty 12 of this invention had leakage in only 23.5f. of the women.
Having thus described the invention in full detail, it will be
readily apparent that various changes and modifications may be made
without departing from the spirit of the invention. All such changes
and modification are contemplated as being within the scope of the
present invention, as defined by the following claims.
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