U.S. patent application number 11/240262 was filed with the patent office on 2006-03-23 for disposable undergarment and related manufacturing equipment and processes.
Invention is credited to Steven C. Gebling, Gregory J. Rajala, Paul D. Suke.
Application Number | 20060064069 11/240262 |
Document ID | / |
Family ID | 37698112 |
Filed Date | 2006-03-23 |
United States Patent
Application |
20060064069 |
Kind Code |
A1 |
Rajala; Gregory J. ; et
al. |
March 23, 2006 |
Disposable undergarment and related manufacturing equipment and
processes
Abstract
This invention pertains to a three dimensional disposable panty,
subassemblies of the panty, and an apparatus and methods for making
the panty and subassemblies. The panty is designed to hold a
primary absorbent sanitary pad. The panty may have elasticized leg
and waist openings and be stretchable about the hip and stomach
regions of a user. the panty provides backup protection to control
egress of fluids that leak or seep around or through the primary
sanitary pad. The panty includes a secondary absorbent positioned
in the crotch area and extending into the body of the disposable
panty, front and back, and preferably over the leg elastics to
trap, inside the panty, leakage from the primary absorbent, and to
prevent strike through onto e.g. outer clothing and bed linen. The
apparatus and methods facilitate assembling leg elastics and crotch
elastics into the panty subassemblies while assembling a series of
panty subassemblies in a continuous web structure at a constant, or
relatively constant, continuous and efficient speed.
Inventors: |
Rajala; Gregory J.; (Neenah,
WI) ; Gebling; Steven C.; (Oshkosh, WI) ;
Suke; Paul D.; (Appleton, WI) |
Correspondence
Address: |
DORITY & MANNING, P.A.
POST OFFICE BOX 1449
GREENVILLE
SC
29602-1449
US
|
Family ID: |
37698112 |
Appl. No.: |
11/240262 |
Filed: |
September 30, 2005 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
09548231 |
Apr 12, 2000 |
|
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11240262 |
Sep 30, 2005 |
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Current U.S.
Class: |
604/385.24 |
Current CPC
Class: |
A61F 13/49017 20130101;
A61F 13/49406 20130101; Y10T 156/1052 20150115; A61F 13/536
20130101; A61F 13/15609 20130101; Y10T 156/1049 20150115; A61F
2013/15463 20130101; A61F 13/534 20130101; A61F 13/496 20130101;
Y10T 156/1062 20150115; A61F 13/505 20130101; A61F 13/15601
20130101 |
Class at
Publication: |
604/385.24 |
International
Class: |
A61F 13/15 20060101
A61F013/15 |
Claims
1. A method for attaching elastic to a crotch area of an
undergarment, the method comprising the steps of: cutting an
elastic thread into a plurality of elastic sections; providing a
secondary absorbent for receipt of at least one of the elastic
sections, the secondary absorbent defining an inner side and an
opposing outer side; attaching the elastic sections to the inner
side of the secondary absorbent as the elastic sections and the
secondary absorbent move in a machine direction; maneuvering the
secondary absorbent with the elastic sections attached thereto to a
non-machine direction; and attaching the secondary absorbent to a
garment web moving in the machine direction, the elastic sections
of the inner side disposed against an inner crotch portion of the
garment web, the opposing outer side visible in the crotch
portion.
2. The method as in claim 1, wherein each elastic section is from
about one inch to about three inches in length.
3. The method as in claim 1, wherein the elastic sections are
attached to the inner side of the secondary absorbent by an
adhesive.
4. A disposable garment assembly, comprising: a disposable garment
defining a length and a width and including an outer cover having a
front body portion and a back body portion, the front body portion
and the back body portion being connected by a crotch portion, the
outer cover, when laid out flat, having a length and a width, the
front body portion and the back body portion being connected
together to form a waist opening, a first leg opening and a second
leg opening, the first and second leg openings having respective
first and second front and back leg edge portions and corresponding
first and second side leg edge portions connecting the front and
back leg edge portions, the outer cover comprising a first layer,
and a second layer having a front portion and a back portion, the
second layer front portion disposed adjacent the front body portion
of the outer cover, the second layer back portion disposed adjacent
the back body portion of the outer cover; a first absorbent
defining a length and a width, each respectively less than the
length and the width of the disposable garment, the first absorbent
further including a liquid impermeable outer sheet and a liquid
permeable inner sheet, the liquid impermeable outer sheet having a
front portion and a back portion, and a center portion
therebetween, each of the liquid impermeable outer sheet front and
back portions of the first absorbent disposed adjacent one of the
respective second layer front and back body portions of the outer
cover, the first absorbent having a first absorbent capacity; a
second absorbent including a first side and a second side and
having a second absorbent capacity, the second absorbent attached
in the crotch portion and covering the width of the first
absorbent, the second absorbent underlying the first absorbent on
the liquid impermeable outer sheet of the first absorbent, the
first side of the second absorbent disposed facing the liquid
impermeable outer sheet, the first absorbent capacity of the first
absorbent being greater than the second absorbent capacity of the
second absorbent; and a plurality of crotch elastics extendably
affixed between the outer cover and the second side of the second
absorbent proximate the crotch portion, the second absorbent
affixed to the outer cover.
5. The disposable garment assembly as in claim 4; wherein the
second absorbent capacity of the second absorbent is about one-half
the absorbent capacity of the first absorbent.
6. The disposable garment assembly as in claim 4, wherein the
second absorbent capacity of the second absorbent is about 3 grams
to about 6 grams.
7. The disposable garment assembly as in claim 4, wherein the
second absorbent capacity of the second absorbent is about 4 grams
to about 6 grams.
8. The disposable garment assembly as in claim 4, wherein the
second absorbent is a stain shield.
9. A disposable garment having a length and a width, and
comprising: an outer cover having front and back body portions
connected by a crotch portion, the outer cover, when laid out flat,
having a length between first and second ends and a width between
first and second sides, the front and back body portions being
connected together to form a waist opening and first and second leg
opening, the outer cover comprising a first layer; a second layer
having front and back body portions overlying respective front and
back body portions of the outer cover; and a stain shield
incorporated into the disposable garment, the stain shield having a
length and a width and a garment facing side, the garment facing
side having a front portion, a back portion and a center portion
therebetween, the garment facing side of the center portion having
a plurality of extensible crotch elastic pieces attached thereto
proximate the crotch portion, the extensible crotch elastic pieces
being disposed between the garment facing side and the outer cover
of the crotch portion, the stain shield affixed to the outer cover,
each of the garment facing side front and back portions of the
stain shield disposed adjacent one of the respective second layer
front and back portions, at least a portion of the stain shield
having an overall total absorbent capacity of about 3 grams to
about 6 grams.
10. The disposable garment as in claim 9, wherein at least a
portion of the absorbent has an overall total absorbent capacity of
about 4 grams to about 6 grams.
Description
RELATED APPLICATIONS
[0001] The present application is a continuation-in-part
application of and claims priority to co-pending U.S. patent
application Ser. No. 09/548,231, filed Apr. 12, 2000 which is
incorporated herein by reference in its entirety.
BACKGROUND OF THE INVENTION
[0002] Undergarments are made typically of cotton and/or synthetic
materials. The cotton and synthetic panties typically do not offer
barrier protection. Often the synthetic undergarments 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., liquid penetrates from
the interior to the exterior of the panty.
[0003] Panty liners and feminine care sanitary napkins or pads used
with regular undergarments have polyethylene backings that provide
some barrier properties inhibiting liquid strike through. However,
if the vaginal discharge extends to the sides or the ends of the
pads, the discharge can leak or seep around an edge of the pad and
onto the undergarment. Such leakage can stain the undergarment.
Depending upon the amount of leakage, liquid may strike through or
go around the undergarment and stain outer clothing and/or bedding.
Women with heavy liquid flows may 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 around the edges of the pads and/or staining of outer
clothing. In some cases, during their heaviest flow days, some
women will restrict their activities and stay home.
[0004] Many 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 more prevalent leakage onto the wearer's outer clothing on pads
worn during heavy flow. Normally this leakage occurs at the side of
the pad, 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 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 typically due to
incompatibility between the pad width and the panty crotch width
and/or lack of barrier properties in the panty material around the
edge portion of the pad.
BRIEF SUMMARY OF THE INVENTION
[0005] The present invention broadly includes a three dimensional,
disposable, discrete panty, subassemblies of the panty, and
apparatus and methods for making the panty.
[0006] In one aspect of the invention, a method for attaching
elastic to a crotch area of an undergarment includes the steps of
cutting an elastic thread into a plurality of elastic sections;
providing a secondary absorbent for receipt of at least one of the
elastic sections, the secondary absorbent defining an inner side
and an opposing outer side; attaching the elastic sections to the
inner side of the secondary absorbent as the elastic sections and
the secondary absorbent move in a machine direction; maneuvering
the secondary absorbent with the elastic sections attached thereto
to a non-machine direction; and attaching the secondary absorbent
to a garment web moving in the machine direction, the elastic
sections of the inner side disposed against an inner crotch portion
of the garment web, the opposing outer side visible in the crotch
portion. In this aspect, each elastic section is from about one
inch to about three inches in length. Also in this aspect, the
elastic sections are attached to the inner side of the secondary
absorbent by an adhesive.
[0007] According to a further aspect of the invention, a disposable
garment assembly includes a disposable garment defining a length
and a width and including an outer cover having a front body
portion and a back body portion, the front body portion and the
back body portion being connected by a crotch portion, the outer
cover, when laid out flat, having a length and a width, the front
body portion and the back body portion being connected together to
form a waist opening, a first leg opening and a second leg opening,
the first and second leg openings having respective first and
second front and back leg edge portions and corresponding first and
second side leg edge portions connecting the front and back leg
edge portions, the outer cover comprising a first layer, and a
second layer having a front portion and a back portion, the second
layer front portion disposed adjacent the front body portion of the
outer cover, the second layer back portion disposed adjacent the
back body portion of the outer cover; a first absorbent defining a
length and a width, each respectively less than the length and the
width of the disposable garment, the first absorbent further
including a liquid impermeable outer sheet and a liquid permeable
inner sheet, the liquid impermeable outer sheet having a front
portion and a back portion, and a center portion therebetween, each
of the liquid impermeable outer sheet front and back portions of
the first absorbent disposed adjacent one of the respective second
layer front and back body portions of the outer cover, the first
absorbent having a first absorbent capacity; a second absorbent
including a first side and a second side and having a second
absorbent capacity, the second absorbent attached in the crotch
portion and covering the width of the first absorbent, the second
absorbent underlying the first absorbent on the liquid impermeable
outer sheet of the first absorbent, the first side of the second
absorbent disposed facing the liquid impermeable outer sheet, the
first absorbent capacity of the first absorbent being greater than
the second absorbent capacity of the second absorbent; and a
plurality of crotch elastics extendably affixed between the outer
cover and the second side of the second absorbent proximate the
crotch portion, the second absorbent affixed to the outer
cover.
[0008] In this aspect of the invention, the second absorbent
capacity of the second absorbent is about one-half the absorbent
capacity of the first absorbent. For instance, the second absorbent
capacity of the second absorbent can be about 3 grams to about 6
grams, more particularly, about 4 grams to about 6 grams. Also in
this aspect of the invention, the second absorbent is a stain
shield.
[0009] In a further aspect of the invention, a disposable garment
has a length and a width, and includes an outer cover having front
and back body portions connected by a crotch portion, the outer
cover, when laid out flat, having a length between first and second
ends and a width between first and second sides, the front and back
body portions being connected together to form a waist opening and
first and second leg opening. The outer cover in this aspect
includes a first layer; a second layer having front and back body
portions overlying respective front and back body portions of the
outer cover; and a stain shield incorporated into the disposable
garment, the stain shield having a length and a width and a garment
facing side, the garment facing side having a front portion, a back
portion and a center portion therebetween, the garment facing side
of the center portion having a plurality of extensible crotch
elastic pieces attached thereto proximate the crotch portion, the
extensible crotch elastic pieces being disposed between the garment
facing side and the outer cover of the crotch portion, the stain
shield affixed to the outer cover, each of the garment facing side
front and back portions of the stain shield disposed adjacent one
of the respective second layer front and back portions, at least a
portion of the stain shield having an overall total absorbent
capacity of about 3 grams to about 6 grams. Also in this aspect, at
least a portion of the absorbent has an overall total absorbent
capacity of about 4 grams to about 6 grams.
BRIEF DESCRIPTION OF THE DRAWINGS
[0010] 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:
[0011] FIG. 1 is a plan view of a garment subassembly according to
an aspect of the invention;
[0012] FIG. 2 is a plan view of the garment subassembly of FIG. 1,
including a secondary absorbent in the crotch;
[0013] FIG. 3 is a cross section of the garment subassembly taken
along line 3-3 of FIG. 2;
[0014] FIG. 4 is a cross section of the garment subassembly taken
along line 4-4 of FIG. 2;
[0015] FIG. 5 is a perspective view of a disposable panty according
to another aspect of the invention;
[0016] FIGS. 6 and 7 are enlarged cut-away views of a fragment of
the subassembly of FIG. 1, particularly showing cross-crotch
elastics in detail;
[0017] FIG. 8 is a side elevation view of an equipment layout for
fabricating and processing subassemblies according to another
aspect of the invention;
[0018] FIGS. 9 and 10 are pictorial views of a nip area of the
elevation shown in FIG. 8;
[0019] FIG. 11 is a plan view showing transverse positioning of
front and back leg elastics along an advancing web as an outer
cover layer and a body side layer are being joined according to an
aspect of the invention;
[0020] FIG. 12 is a plan view as in FIG. 10, showing an alternate
pattern for elastic threads; and
[0021] FIG. 13 is a perspective view showing steps in a method for
cutting a plurality of elastics and attaching the elastics to a
secondary absorbent according to another aspect of the
invention.
DETAILED DESCRIPTION OF THE INVENTION
[0022] The following detailed description is made in the context of
an article including a disposable panty, and corresponding panty
subassemblies, for holding a sanitary pad in place as a primary
absorbent during use of the panty. It is readily apparent, however,
that the present invention can be employed with other disposable
sanitary articles, such as feminine tampons, incontinent garments
and the like.
[0023] The panty subassembly 10 of FIG. 1 illustrates an embodiment
of a two-layer panty subassembly prior to incorporation of the
secondary absorbent. The panty subassembly of FIG. 2 illustrates
the finished panty including all elements, but before the final
steps of assembling the composite to form the panty structure. FIG.
5 shows the finally-assembled disposable panty structure.
[0024] Referring to FIGS. 1-3, the panty subassembly 10 has an
outer cover layer 12 generally defining the overall length "L1" and
width "W1" of the subassembly, and a body side layer 14 secured to
the outer cover layer. The panty subassembly 10 generally includes
a front body portion 16 terminating at a front waist portion 18 as
a first edge of the subassembly, a back body portion 20 terminating
at a back waist portion 22 as a second edge of the subassembly, and
a crotch portion 24.
[0025] The body side layer 14 includes a front layer element 19
generally overlying and secured to the outer cover layer 12 on the
front body portion 16, and a back layer element 21 generally
overlying and secured to the outer cover layer 12 on the back body
portion 20. A space 23 separates the front layer element 19 from
the back layer element 21.
[0026] Referring to FIGS. 2 and 5, for assembling the subassembly
of FIG. 2 to form a panty 25 as in FIG. 5, a first side edge 26 of
front body portion 16 is assembled with a first side edge 28 of the
back body portion 20 to form a first side seal 30. Similarly, a
second side edge 32 of the front body portion 16 is assembled with
a second side edge 34 of the back body portion 20 to form a second
side seal 36. The waist portions 18, 22 when assembled form a waist
opening 38 for putting on and taking off the panty 25. The waist
opening 38 is surrounded at least in part by a waist elastic 40.
The waist elastic 40 is stretched and attached to the waist
portions 18, 22 in the stretched state. The waist elastic 40 is
released after attachment to produce waist folds or pleats 42 to
allow expansion of the waist opening 38 so that the panty 25 can
fit various sizes of people. Because users of this invention
generally prefer a brief style panty, the front waist portion 18
preferably comes as high as the navel and is level around the
wearer's waist. Having the panty at this height provides a snug
fit. Alternative panty styles include bikini (e.g. regular leg cut
or french leg cut) and hipster (e.g. regular leg cut or french leg
cut).
[0027] Referring to FIGS. 1 and 5, the front body portion 16, the
back body portion 20, and the crotch portion 24, in combination,
form left and right leg openings 44 and 46, respectively, which are
generally circular or oval in shape in the finally assembled panty
25. The leg openings 44 and 46 are formed by cutting away portions
of the outer cover layer 12, and corresponding portions if any of
body side layer 14. Each leg opening 44, 46 is surrounded at least
in part by a back leg elastic 48, a front leg elastic 50, and a
crotch elastic 51 between the back leg elastic and the front leg
elastic. Each of the respective elastics 48, 50, 51 is adjacent the
respective one of the edges 52 of the corresponding leg openings.
The front and back leg elastics 48, 50 are secured between the
outer cover layer 12 and the body side layer 14 by adhesive 55. The
crotch elastics 51 are secured between outer cover layer 12 and a
crotch elastic support sheet 53, also by adhesive 55. The elastics
48, 50, 51 are in the stretched state when secured to the outer
cover layer 12. Accordingly, when the elastics, the outer cover
layer, the body side layer, and the support sheet 53, are released
after the elastics are secured to the outer cover layer, the
elastics produce leg folds or pleats 54 at the edges of the leg
openings 44, 46 to allow expansion of the leg openings 44, 46 to
fit various sizes of legs.
[0028] The front body portion 16 may be divided into a front upper
portion 56 and a front lower portion 58. Similarly, the back body
portion 20 may be divided into a back upper portion 60 and a back
lower portion 62. The upper portions 56 and 60 are preferably
designed to include body elastics 64 which readily stretch to allow
the wearer to put on the panty 25 and then readily contract to
resume the normal release state of the body elastics. This ensures
a close or snug fit to different body sizes and forms. A number of
body elastics 64 are positioned on both the front and the back
portions 56, 60, respectively, at positions between the waist
opening 38 and the leg openings 44, 46, so that the panty 25 has a
good fit, particularly around the body.
[0029] The lower body portions 58, 62 generally do not require the
spaced elastics as in the upper body portions 56, 60, although the
elastic threads may be used.
[0030] The width of the crotch portion 24 between the left and
right crotch elastics 51 should be wide enough to accommodate
laying the primary absorbent 66 between the edges 52 without having
the primary absorbent 66 obstruct the crotch elastics 51. This
allows the crotch elastics 51 to contract and draw up the sides of
the crotch about the primary absorbent, to thus accommodate the
thickness of the primary absorbent 66, and to give surface area
within the crotch portion 24 of the panty, adjacent edges 52, to
contain leakage from the primary absorbent 66.
[0031] The width of the crotch portion 24 between the elastics 51
should not be so wide as to seem bulky or uncomfortable. A suitable
width is at least about 2.75 inches (70 mm) between the crotch
elastics. Width of crotch portion 24 is advantageous from about 3
inches (76 mm) to about 3.5 inches (89 mm). Preferably, the width
is about 3 inches (76 mm).
[0032] Preferably, the crotch elastics 51 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 (13 mm). Preferably, ruffle material on the
edge of the leg openings 44, 46 outside the leg and crotch elastics
48, 50, 51 is less than about 0.25 (6 mm). More preferably, the
ruffle material is less than about 0.125 inch (3 mm). It is most
desirable to eliminate any ruffle material from the edges of the
leg openings 44, 46.
[0033] The overall width of the crotch portion 24 includes the
width between the left and right crotch elastics 51, the width of
the crotch elastics, and any ruffle material outside the crotch
elastics to the edges 52 of the leg openings. Preferably, the
overall width of the crotch portion 24 should be at least about 4
inches (102 mm).
[0034] FIG. 2 shows the panty subassembly 10 of FIG. 1 with a
secondary absorbent 68 secured in the crotch portion 24, over the
outer cover layer 12 and parts of the front and back layer elements
19, 21 of the body side layer 14. The width of the secondary
absorbent 68 is sized in relation to the width of the crotch
portion 24. Preferably, the width of the secondary absorbent 68 is
at least the width of the crotch portion 24 between the crotch
elastics 51. More preferably, the width of the secondary absorbent
is equivalent to the overall width of the crotch portion 24.
[0035] The secondary absorbent 68 should have sufficient capacity
to absorb any flow or seepage of body fluid around or through the
primary absorbent 66. The secondary absorbent 68 should preferably
have a capacity and thickness substantially less than that of the
primary absorbent 66, thus providing a nonbulky and flexible fit.
The secondary absorbent 68 should have a total capacity of about
one-half the capacity of the primary absorbent 66. Preferably, the
secondary absorbent 68 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 68 should be from about 4 grams
to about 6 grams. However, the basis weight of, or the type of, the
secondary absorbent 68 should be selected to provide resistance to
flexibility of less than around 400 grams, as measured by INDA
Standard Test method IST 90.3-92 Standard Test Method for
Handle-O-Meter Stiffness of Nonwoven Fabrics.
[0036] The secondary absorbent has a low stiffness. The low
stiffness allows the absorbent and its barrier to remain attached
to the conformable outer cover layer 12 and the body side layer 14
which conform to a wide range of body sizes and shapes. Preferably,
the secondary absorbent has a stiffness of less than 400 grams
along any axis tested, more preferably less than 300 grams along
any axis and less than 100 grams along the axis parallel to the
waist opening. The secondary absorbent alone will have a stiffness
of less than 250 grams and preferably less than 100 grams along any
axis and more preferably less than 75 grams along the axis parallel
to the waist opening.
[0037] The overall length of the secondary absorbent 68 should be
adequate to extend beyond the ends of the primary absorbent 66, in
order to be properly positioned to receive liquid which flows or
seeps around the edges of the primary absorbent 66. This overall
length is typically at least about 15 inches (382 mm) thus
extending beyond the crotch portion 24 along the longitudinal
centerline A-A of the subassembly 10. The length should be in the
range of about 15 inches (382 mm) to about 19 inches (484 mm).
Preferably, the length of the secondary absorbent 68 is about 17
inches (433 mm).
[0038] The width of the secondary absorbent 68 beyond the crotch
portion 24 should be at least as wide as the width of the crotch
portion 24. The width of the secondary absorbent 68 may be narrowed
beyond the crotch portion 24 but may thus compromise the
containment of liquid flowing or seeping from the primary
absorbent. More preferably, the width outside the crotch portion is
wider than in the crotch portion, and is from about 5 inches (127
mm) to about 12 inches (306 mm), alternatively from about 5.5
inches (140 mm) to about 7.5 inches (191 mm). Preferably, the width
is about 6.5 inches (165 mm).
[0039] Referring to FIGS. 2, 3, and 4, the waist elastics 40, the
body elastics 64, and the leg elastics 48, 50, 51 are generally
covered by the front and back layer elements 19, 21 of the body
side layer 14.
[0040] Both outer cover layer 12 and body side layer 14 are
compliant and soft feeling to the wearer. The following description
of materials from which the outer cover layer 12 can be made
applies equally to the material of the body side layer 14.
[0041] The outer cover layer 12 may be liquid pervious, permitting
liquids to readily penetrate into its thickness, or impervious,
resistant to the penetration of liquids into its thickness. Outer
cover layer 12 may be made 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. The outer cover layer 12 may be woven, nonwoven such as
spunbonded, carded, or the like. A suitable outer cover layer 12 is
carded, and thermally bonded by means well known to those skilled
in the fabric art. Alternatively, the outer cover layer 12 is
derived from a spunbonded web. In preferred embodiments, the outer
cover layer is spunbonded polypropylene nonwoven with a wireweave
bond pattern having a grab tensile of 19 pounds as measured by ASTM
D1682 and Do, a Taber 40 cycle abrasion rating of 3.0 as measured
by ASTM Do and Handle-O-Meter MD value of 6.6 grams and CD value of
4.4 grams using TAPPI method To. Such spunbonded material is
available from Kimberly-Clark Corporation, Roswell, Ga. The outer
cover layer 12 has a weight of from about 0.3 ounce per square yard
(osy) to about 2.0 osy, preferably about 0.7 osy.
[0042] The position and shape of the leg openings 44, 46 are
important to avoid tightness in the crotch and groin area of the
wearer, to obtain adequate buttocks coverage, and to prevent the
panty 25 from tilting forward, e.g. tilting such that the front
waist edge dips lower in relationship to the back waist edge. FIGS.
1 and 2 illustrate the most preferred design for leg fit and
buttocks coverage. The shape of the curve across the top of the leg
is important. If the curve is too deep, the panty 25 will shift
downward and backward resulting in a short front waist, increased
back length and bagginess in the seat of the panty. This would
cause the panty 25 to appear tilted when worn as evidenced by an
unevenness around the waist of the wearer.
[0043] Thus, the majority of the edge 70 of the front portion of
each leg opening 44, 46 is defined by a straight section 72 having
a length "L2" at least about 70% of the length "L3" of the entire
edge 70. The straight section 72 should form an angle with the
centerline A-A of between about 75 degrees and about 100 degrees,
and most preferably about 90 degrees.
[0044] With the panty subassembly 10 laid out flat as in FIG. 1,
the majority of the edge 74 of the back portion of each leg opening
is defined by a straight section 76 having a length "L4" at least
about 70% of the length "L5" of the entire edge 74. The straight
section 76 forms an acute angle with the longitudinal centerline
A-A of the subassembly 10. More preferably, the straight section 76
of the edge 74 forms an acute angle a with the centerline A-A of
the panty 25 of between about 50 degrees and 65 degrees and most
preferably about 60 degrees.
[0045] The majority of the edge 78 of the crotch portion of each
leg opening 44, 46 is defined by a straight section 80 having a
length "L6." Preferably, the straight sections 80 are straight for
at least about 70% of the entire lengths "L7" of the respective
edges 78.
[0046] Each back leg edge portion 74 includes an arcuate section
"A1" extending from one end 81 of the respective straight section
76 to a second end 82 connecting the respective back leg edge
portion.
[0047] Each front leg edge portion 70 includes an arcuate section
"A2" extending from one end 84 of the respective straight section
72 to a second end 86 connecting the respective front leg edge
portion 70 to the front end of edge 78 of the respective crotch
portion.
[0048] The shape of the arcuate section "A2" at the inner groin
area is important. If the arc is too shallow, tightness may be
experienced at the inner groin area.
[0049] The preferred narrow crotch width reduces coverage of the
buttocks. To compensate for such reduction, the arcuate section
"A1" is preferably adjusted toward back waist portion 22, such that
the end 82 of the arcuate section "A1" should be positioned
slightly forward of centerline B-B as shown in FIGS. 1 and 2.
[0050] The waist, leg, and body elastics 40, 48, 50, 64
respectively are attached to the panty subassembly 10, generally
between the outer cover layer 12 and the body side layer 14, using
apparatus and processes described hereinafter.
[0051] Materials suitable for elastics include a wide variety
including but not limited to elastic strands, yarn rubber, flat
rubber (e.g. as bands), elastic tape, film-type rubber,
polyurethane, and, tape-like elastomer, or foam polyurethane or
formed elastic scrim. Each elastic may be unitary, multipart, or
composite in construction.
[0052] Waist elastic 40 is typically 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. Preferably, the waist elastic is threads, more
preferably four threads are used as the elastic and the threads are
spaced about 0.17 inch (4.3 mm) apart. The threads may be made of
any suitable elastomeric material. One suitable material is spandex
such as Lycra.RTM. threads available from Dupont located in
Wilmington, Del. Suitable waist elastics include threads having a
total decitex (g/1000 m) of about 3760 for 0.5 inch (13 mm) wide
elastic. Adhesive 55 is used to bond the elastic between the outer
cover layer 12 and the body side layer 14. A suitable adhesive
includes, for example Findley H2096 hot melt adhesive, available
from Findley Adhesives, Milwaukee, Wis.
[0053] The leg elastics 48, 50, and crotch elastic 51, including
multiple threads in each, are typically about 0.5 inch (13 mm)
wide. The elastic may comprise threads, ribbons, a film or
composite. The threads, ribbons, etc., may be multiple and may be
applied as a composite. The front leg elastics and the crotch
elastics may be threads, preferably numbering three threads which
are spaced about 0.17 inch (4.3 mm) apart. Back leg elastics
numbering up to six threads may have a width of about 0.75 inch (19
mm) and a spacing of about 0.15 inch (3.8 mm) apart. The threads
may be made of any suitable elastomeric material. One suitable
material is spandex such as Lycra.RTM. threads available from
Dupont, Wilmington, Del. Suitable leg elastics include threads
having a total decitex (g/1000 m) of about 3760 for a 0.5 inch (13
mm) wide elastic. Adhesive 55 is used to bond the several elastics
48, 50, and 51 to the outer cover layer 12, the body side layer 14,
and the support sheet 53.
[0054] To provide a snug leg fit and to draw up the sides of the
crotch portion 24 to a cradle to receive the primary absorbent, the
leg elastics 48, 50, and the crotch elastics 51, are elongated when
applied to the layers 12 and 14 respectively. Preferably, the leg
elastics 48, 50 are applied in multiple segments, with the amount
of elongation of each segment while being incorporated into the
subassembly 10 being determined according to the position to be
occupied by the respective segment. In the case of only front and
back leg elastics, the front leg elastics are elongated less than
the back elastics. In the case of front elastics, back elastics,
and crotch elastics, the front and crotch elastics are elongated
less than the back elastics. Preferably, the front and crotch
elastics are elongated to about 150% and the back elastics along
the leg openings are elongated to about 250% The differing tensions
allow easier attachment of the primary absorbent pad 66, less
tightness in the groin area, and less bunching of the crotch
portion 24 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.
[0055] Referring now to FIGS. 1, 6, and 7, the suggested six (back)
and three (front) threads of elastic on the respective back and
front leg elastics 48 and 50 are each represented as single threads
112 of elastic. The following description of the characteristics
and use of the single threads applies to the usual multiple threads
suggested above.
[0056] The composite of the elastics extending about each of the
leg openings 44 and 46 comprises a portion of the back leg elastics
48, a portion of the front leg elastics 50, and one of the left and
right crotch elastics 51. Referring specifically to FIGS. 1, 6, and
7, the back leg elastic 48 extends, as a first section 48A, from a
first locus 92 at or propinquant the edge 28 of the subassembly,
width-wise across the subassembly at a substantially consistent
acute angle a with the centerline A-A that takes it toward a first
edge of the subassembly at front waist portion 18, and generally
following the back edge 74 of the leg opening 46 along the straight
section 76A and onto the first arcuate section "A1" toward the
crotch portion 24, generally terminating in the first arcuate
section "A1," at or near the crotch portion 24. Back leg elastic 48
extends, as a second section 48B, from the first arcuate section
"A1" across the crotch portion to the second arcuate section "A1."
From the second arcuate section "A1," the back leg elastic 48
extends, as a third section 48C, at an acute angle a with the
centerline A-A away from the front waist portion 18, and generally
following the back edge 74 of the leg opening 44 along the straight
section 76B to a second locus 94 at or propinquant edge 34. In the
flat configuration shown for the subassembly in FIGS. 1, 6, and 7,
sections 48A and 48C are elongated 250%, while section 48B is
relaxed, and under no substantial elongation. Preferably, section
48B includes a modest amount of slack in the elastic.
[0057] The front leg elastic 50 extends, as a first section 50A,
from a third locus 96 at or propinquant the side edge 26 of the
subassembly width-wise across the subassembly and generally
following the front leg edge portion 70 along its longitudinal
straight section 72A, and onto the first arcuate section "A2"
toward the crotch portion 24, generally terminating in the first
arcuate section "A2," at or near the crotch portion 24. Front leg
elastic 50 extends, as a second section 50B, from the first arcuate
section "A2" across the crotch portion to the second arcuate
section "A2." From the second arcuate section "A2," the front leg
elastic 50 extends, as a third section 50C, width-wise across the
subassembly and generally following the front leg edge portion 70
along its longitudinal straight section 72B to a fourth locus 98 at
or propinquant side edge 32. In the flat configuration shown for
the subassembly in FIGS. 1, 6, and 7, sections 50A and 50C are
elongated 150%, while section 50B is relaxed, and under no
substantial elongation. Preferably, section 50B includes a modest
amount of slack in the elastic.
[0058] Thus, in the embodiment seen in FIGS. 1, 2, 6, and 11, the
front and rear leg elastics extend across the width W1 of the
subassembly 10 as one or more continuous threads.
[0059] The crotch elastics 51 extend generally between the back and
front leg elastics 48 and 50, with respective ends of the crotch
elastics generally being disposed at or near the arcuate sections
"A1" and "A2." Accordingly, the elastic properties extant about
each leg opening result from the combined contributions of the
respective back leg section (e.g. 48A), the respective front leg
section (e.g. 50A), and the respective crotch elastic 51.
[0060] The reason for providing leg elastics in multiple sections
is at least two-fold. First, using multiple sections of elastics
facilitates placing of the elastics on the outer cover layer 12
while maintaining advantageous production speeds. As suggested in
FIGS. 1, 8, and 9, the subassembly of e.g. FIG. 1 is made as a
sequence of such subassemblies in a continuous web 100, with the
width "W1" of the subassembly disposed in the "with machine"
direction of the processing apparatus. In such arrangement, the
front and back waist elastics 40, the front and back body elastics
64, and the front and back leg elastics 48, 50 can all be assembled
into the subassembly by appropriate continuous feeding of
respective continuous threads of elastics into the processing
apparatus in the "with machine" direction while the web 100
continuously advances in the "with machine" direction at a constant
speed.
[0061] Given the orientation of the crotch elastics at essentially
90 degrees to the direction of advance of the web 100, placing the
crotch elastics as a portion of a continuous element of either the
front or back leg elastics would suggest either (1) momentarily and
regularly stopping the advance of the web 100 while the crotch
elastic is fed into place, or (2) severely slowing the web 100 and
severely driving an elastics guide, in a direction transverse to
the web in order to apply the crotch elastic while the web was thus
slowed. In either scenario, severe stresses would be placed on the
respective drive apparatus, as well as on the web. The invention
contemplates, rather, that the crotch elastics are placed in the
subassembly 10 as a separate operation placing separate elastics
segments, where the crotch elastics segments are first elongated
and oriented transverse to the web 100, and are then placed on the
web as the web passes the appropriate operating station (not shown)
subsequent to placing the leg, body and waist elastics in the
subassembly, though the sequence of placing the elastics is not
critical.
[0062] Referring now to FIGS. 8 and 9, a first continuous web,
which ultimately becomes cover layer 12, is pressed against the
assembly roll 102 by turning roll 104. A second continuous web,
which ultimately becomes body side layer 14, passes under adhesive
applicator 106 and over turning rolls 108 and 110, and is pressed
against the assembly roll 102 by turning roll 110. Elastic threads
112 are fed from a continuous supply 114 of elastic thread, through
feed nip 116, through thread guides 118 and sets of guide fingers
120A and 120B, and between cover layer 12 and body side layer 14 at
the nip formed by assembly roll 102 and turning roll 110.
[0063] Referring especially to FIGS. 10 and 11, thread guides 118
and corresponding sets of guide fingers 120A and 120B are elements
of lateral guides 122A and 122B respectively. Each of the lateral
guides 122A and 122B is mounted on a transverse slide bar 124 for
sliding transverse to the with machine direction of travel of the
webs. Each lateral guide 122 is connected to a transverse drive
mechanism 126 including linkage arms 128 and 130, vertical drive
shaft 132, and a cam follower inside cam housing 136. The cam
followers follow the corresponding cams inside the respective cam
housings. The cams are linked to the machine drive shaft 140 by
drive belt 142. Thus, the cams, and correspondingly the thread
guides and the sets of guide fingers, move transversely with
respect to the with machine direction of the webs as the drive
shaft turns. The end result is that rotation of the processing line
drive shaft 140 effects transverse motion of the thread guides and
the sets of guide fingers, as indicated by the arrows in FIG. 10,
in cooperation with the design of the cams and cam followers.
[0064] Referring to FIG. 8, the guide fingers 120 are positioned
close to the nip 144 so that they closely control the transverse
positions of the elastics with respect to the webs 12 and 14 as the
webs 12 and 14 enter the nip 144 and correspondingly trap the
elastics between them, fixing the position of the elastics between
them by means of adhesive 55. Accordingly, the guide fingers 120
are preferably physically positioned, and provide guidance to the
threads of elastic, within one inch of the nip 144. To the extent
the fingers can be placed closer to the nip 144, they provide more
positive guidance to the elastic. By careful design of the guide
fingers 120, and by careful control of the positioning of the guide
fingers 120 with respect to nip 144, the guide fingers 120 can be
advantageously positioned within 0.5 inch of the line of contact
defined at the nip between roll 102 and 108.
[0065] The limitation on how close the guide fingers 120 can be
placed to the nip is controlled by the ability to design fingers
which can affirmatively guide the threads of elastic while avoiding
having the fingers themselves drawn into the nip. The criticality
of urging the fingers as ultimately close as possible to the nip
can be attenuated by directing the threads 112 onto the
adhesive-coated layer 14 ahead of nip 144, preferably
instantaneously ahead of the nip 144, as suggested by the depiction
in FIG. 8. By directing the threads of elastic onto layer 14 ahead
of the nip, the open distance spanned by the threads between the
fingers 120 and the adhesive-coated layer 14 is minimized, being
held to less than 0.5 inch, for example 0.25-0.375 inch (6 mm to 10
mm).
[0066] The transverse movement of the lateral guides 122, and thus
fingers 120, as the webs advance along the processing line, creates
transverse positioning of the elastics threads 112 with respect to
the with machine direction of the advancing webs 12 and 14. FIG. 11
shows the pattern of transverse movement of the sets of guide
fingers 120A and 120B relative to the movement of the web in the
with machine direction, along the processing line. In FIG. 11, the
sets of fingers 120A and 120B are depicted at several locations
along the front and back edges of the leg openings 44, 46, to
indicate that it is the positioning of the sets of fingers 120A and
120B, and the dynamic changing of that positioning by the drive
mechanism 126, that determines the instantaneous transverse
location of the elastics in the web at any point and time while the
elastics are being placed in the web at nip 144 as shown in FIGS.
8-11. Comparing FIGS. 1, 10, and 11, it is seen that the set of
fingers 120A generally places the threads of the back leg elastics
generally parallel to each other in the web, while the set of
fingers 120B generally places the threads of the front leg elastics
generally parallel to each other in the web, both along their
respective portions of the designed paths defining the front 70 and
back 74 edges of the leg openings 44 and 46. The threads of elastic
deviate slightly from their parallel relationships with each other
as the elastic threads traverse paths that deviate from the with
machine direction, the distance between the threads 90 being
generally constant as they emerge from the fingers 120. Such
deviations from the parallel, resulting from the cross machine
traverse of the elastics, are included herein within the phrase
"generally parallel" as respects the relationships of the threads
of elastic to each other.
[0067] It will be understood that FIG. 11 represents only one panty
in the continuous sequence of panty subassemblies 10 contained in
the web 100 passing through nip 144. It will also be understood
that the web passing through the nip 144 is further acted upon at
cutter 146 to cut away material from the web 100 in creating the
leg openings 44 and 46.
[0068] In general, then, webs 12 and 14 are provided as
substantially endless rolls from unwind stands (not shown). Web 14
is typically provided as front and back layer elements 19 and 21.
Space 23 separates the elements 19 and 21, and generally
corresponds with the crotch portion and the portion of the web 12
which is cut out to form leg openings 44 and 46. Adhesive 55 is
applied to the front and back elements 19 and 21 of web 14 by
adhesive applicator 106. Webs 12 and 14 are joined adhesively, with
elastic threads being interposed between webs 12 and 14 at nip 144,
and with space 23 interposed between the front and back elements
19, 21 of the body side layer 14. The transverse positions of the
elastics change according to a pre-set path of transverse
movements, driven by the drive shaft 140 which drives and times the
several operations along the processing line. The threads of
elastic 112, as placed by the guide fingers 120, traverse
respective paths that ultimately follow the front and back edges of
the leg openings 44 and 46, as defined at cutter 146, in
registration with the advance of the web, and accordingly, with the
advance of the series of panty subassemblies 10 being defined in
the web at nip 144 and cutter 146. The portions of the threads of
elastic located along the front and back edges of the leg openings
are stretched. The portions traversing the crotch portion are
relaxed. The crotch portions of the elastic are separately placed
in the subassembly 10 at a later processing station, preferably
downstream from the cutter 146.
[0069] A second embodiment of the subassembly is illustrated in
FIG. 12. In the second embodiment, the front edge 148 of back layer
element 21 is disposed rearwardly of that same edge 148 as depicted
in the embodiment of FIG. 10, while the guide fingers 120A traverse
the same path as in FIG. 10. Accordingly, as the threads of elastic
112 extend across the crotch portion 24, the threads 112 are guided
forwardly of edge 148, into space 23, and are thus not held between
the layers 12 and 14, and thus are not controlled by the adhesive
on layer 14. Rather, the tension is maintained on the threads of
elastic 112 across the crotch portion 24, such that the threads
retract along the edge 148 of the layer element 21 in a
configuration that loosely resembles a rope under tension. The rope
is subsequently cut such that the cut portions of the threads
retract to positions generally defined by the intersection of the
edge 148 of the back layer element 21 and the path of the threads
adhesively held between layer 12 and the back layer element 21.
Thus, the threads 112 generally include loose intermediate ends 150
after being cut, as shown in FIG. 7.
[0070] Body elastics 64 and waist elastics 40 can be incorporated
at nip 144 in the conventional manner of providing stationary feeds
and guides at the nip.
[0071] In another embodiment of the invention shown in FIG. 13, a
section of web processing equipment 297 is shown including a drive
side DS and an operator side OS. As generally shown, a plurality of
elastic threads 212 are attached to a stain shield or secondary
absorbent web 267, and the secondary absorbent 267 and attached
elastic threads 212 are cut to create a plurality of stain shields
268 having respective elastic pieces or sections 251A attached
thereto. The elasticized stain shields 268 are maneuvered as shown
and attached to a garment web 201 to form a garment blank
subassembly. This garment blank subassembly is similar in many ways
to the embodiments described above; therefore, only certain
features of this embodiment are described below for the sake of
brevity and reference is made to the foregoing descriptions for
like or similar components of the garment blank subassembly to
enable this aspect of the invention.
[0072] With more particular reference to FIG. 13, the processing
equipment 297 supplies the plurality of elastic threads 212 from an
elastic thread roll 214 generally in a machine direction MD. The
elastic threads 212 are routed by a series of guide rollers G in a
known manner and are attached in a stretched condition in a
non-machine direction (NMD) in this example to the secondary
absorbent web 267 using an adhesive 255A. As shown, the adhesive
255A is applied intermittently to the elastic threads 212 by a
plurality of applicators 206A to form a plurality of adhesive gaps
213 along the elastic threads 212. The cutter 246 cuts the
secondary absorbent web 267 into the stain shields 268 at each
adhesive gap 213. As further shown, the stain shield 268 the
resultant sections 251A are attached to a first or inner side 268B,
which opposes a second or outer side 268A discussed further
below.
[0073] The exemplary cutter 246 shown in FIG. 13 is a roller cutter
having a plurality of blades 246A,B attached thereto for cutting
the elastic sections 251A at the adhesive gaps 213 as discussed
above. The cutter 246 is controlled by a controller 299 disposed on
the operator side OS of the processing equipment 297 in this
example. Those skilled in the art will instantly recognize that the
controller 299 can be a computer or a programmable logic
controller, which can be programmed to cut the elastic threads 212
at the adhesive gaps 213 based on a passage of time or a sensed
length of passing elastic threads 212 to create the sections 251A.
As shown, each end of each section 251A, which formed the gaps 213
in the elastic threads 212 before the elastic threads 212 were cut,
retract after being cut to create a retraction area 268C on the
outer side 268B. In this example, the sections 251A are from about
one (1) inch to about three (3) inches in length.
[0074] As further shown in FIG. 13, a second adhesive applicator
206B applies a second amount of adhesive 255B to the outer sides
268B of the stain shields 268. As shown, a plurality of applicator
assembly segments 297A-D subsequently maneuver or rotate the
adhesive coated stain shields 268 transverse to the machine
direction MD. As further shown, the applicator assembly segments
297A-D affix the adhesive coated outer sides 268B and the
underlying elastic sections 251A to the garment web 201 with the
inner sides 268A facing upward or outward from within a crotch area
or portion 224. As shown, the inner sides 268A are located between
a plurality of garment elastics 251B. In this manner, the
individual elastic sections 251A are rapidly manipulated,
positioned and attached to the crotch area 224 without having to
maneuver the entire garment web 201 and/or cut the elastic threads
212 and apply the elastic sections 251A to the crotch portions 224
through acute angles at high machine speeds.
[0075] Wherever herein this teaching refers to "multiple" elements,
e.g. multiple threads of elastic or multiple paths of traverse, any
two or more such elements are included.
[0076] 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 modifications are contemplated as being within the
scope of the present invention, as defined by the following
claims.
* * * * *