U.S. patent application number 12/854221 was filed with the patent office on 2010-12-02 for elastic composite.
Invention is credited to Kevin P. Black, Dickie J. Brewer, Donald H. Lester, JR., Thierry Marche.
Application Number | 20100304080 12/854221 |
Document ID | / |
Family ID | 39107579 |
Filed Date | 2010-12-02 |
United States Patent
Application |
20100304080 |
Kind Code |
A1 |
Black; Kevin P. ; et
al. |
December 2, 2010 |
ELASTIC COMPOSITE
Abstract
An elastic composite includes a first nonwoven, a second
nonwoven, and two elastic films sandwiched between the first and
second nonwoven. The elastic composite also includes a lateral edge
portion where the first nonwoven is bonded to the second nonwoven,
a lane between the elastic films that is free of the elastic films,
and a first bond joining the first nonwoven to the elastic film,
and a second bond joining the second nonwoven to the elastic film.
The elastic composite may be used as a component of a disposable
garment.
Inventors: |
Black; Kevin P.; (Rock Hill,
SC) ; Brewer; Dickie J.; (Clover, SC) ;
Lester, JR.; Donald H.; (Waxhaw, NC) ; Marche;
Thierry; (La Chapelle Basse Mar, FR) |
Correspondence
Address: |
HAMMER & ASSOCIATES, P.C.
3125 SPRINGBANK LANE, SUITE G
CHARLOTTE
NC
28226
US
|
Family ID: |
39107579 |
Appl. No.: |
12/854221 |
Filed: |
August 11, 2010 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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11840407 |
Aug 17, 2007 |
7794819 |
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12854221 |
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60839998 |
Aug 24, 2006 |
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60889311 |
Feb 12, 2007 |
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Current U.S.
Class: |
428/101 |
Current CPC
Class: |
B29C 66/21 20130101;
B29C 66/43 20130101; B29L 2031/4878 20130101; B32B 2307/51
20130101; B32B 2309/10 20130101; B29C 65/02 20130101; B29C 65/14
20130101; Y10T 442/601 20150401; Y10T 428/24752 20150115; Y10T
442/602 20150401; Y10T 428/2476 20150115; B32B 2305/20 20130101;
Y10T 428/24025 20150115; Y10T 428/24826 20150115; B32B 37/144
20130101; B29C 66/472 20130101; B29C 65/1412 20130101; B29K
2105/0854 20130101; B29C 65/08 20130101; B32B 2555/02 20130101;
B29C 2035/0822 20130101; B29C 66/344 20130101; B29C 65/4815
20130101; D04H 13/00 20130101; Y10T 428/24802 20150115; B32B
2307/718 20130101; B32B 37/1292 20130101; Y10T 428/24793
20150115 |
Class at
Publication: |
428/101 |
International
Class: |
B32B 3/06 20060101
B32B003/06; D04H 13/00 20060101 D04H013/00; B32B 7/14 20060101
B32B007/14 |
Claims
1. An elastic composite comprising: a structure consisting of three
lateral sections, said sections being a lateral edge portion, a
stretch zone, and a lane, with the stretch zone positioned between
the lateral edge zone and the lane, the lateral edge portion and
the lane being substantially inextensible in a CD when compared to
the stretch zone, and the stretch zone being extensible in the CD
when compared to the lateral edge portion or the lane; and the
elastic composite further comprising: a first nonwoven and a second
nonwoven sandwiching an elastic film with lateral edges, the first
nonwoven and the second nonwoven extending beyond the lateral edges
of the elastic film, in the lateral edge portion, the first
nonwoven and the second nonwoven being bonded together so that the
lateral edge portion being substantially inextensible in the CD, in
the stretch zone, the first nonwoven being bonded to the elastic
film with a plurality of laterally spaced apart, stretch zone bonds
that extend in a MD, the second nonwoven is bonded to the elastic
film with a plurality of laterally spaced apart, stretch zone bonds
that extend in the MD, in the lane, the first nonwoven and the
second nonwoven being bonded so that the lane being substantially
inextensible in the CD, whereby when the elastic composite is
stretched in the CD, said nonwovens bonded to the elastic film
extend with the elastic film and when the elastic composite is
relaxed, said nonwovens bonded to the elastic film bulk.
2. The elastic composite according to claim 1 wherein the stretch
zone bonds between either the first nonwoven and the elastic film
or the second nonwoven and the elastic film comprise lines of
adhesives.
3. The elastic composite according to claim 2 wherein the lines of
adhesives may be continuous lines or discontinuous lines.
4. The elastic composite according to claim 2 wherein the adhesive
being a hot melt adhesive.
5. The elastic composite according to claim 2 wherein the adhesive
being inelastic.
6. The elastic composite according to claim 1 wherein each stretch
zone bond having a width in the range of 0.5-1.0 mm.
7. The elastic composite according to claim 6 wherein each stretch
zone bond having a width in the range of 0.5-0.55 mm.
8. The elastic composite according to claim 1 wherein a
center-to-center stretch zone bond spacing being in the range of
2.0-2.5 mm.
9. The elastic composite according to claim 1 wherein the first
nonwoven or the second nonwoven or both being selected from the
group consisting of a point bonded carded nonwoven or a spunlaced
nonwoven.
10. The elastic composite according to claim 9 wherein the first
nonwoven or the second nonwoven or both have a CD/MD elongation
ratio of at least 3:1.
11. The elastic composite according to claim 1 wherein the elastic
film comprising a styrenic block co-polymer.
12. The elastic composite according to claim 1 where in the lane,
the first nonwoven is bonded to the second nonwoven.
13. The elastic composite according to claim 1 where in the lane, a
stiffener is bonded between the first nonwoven and the second
nonwoven.
14. An elastic composite comprising: a first nonwoven, said first
nonwoven being extensible, but inelastic, said first nonwoven being
further characterized by a CD/MD elongation ratio of at least 3:1,
said first nonwoven being a point-bonded carded nonwoven made of
staple fibers or a spunlaced nonwoven, a second nonwoven, said
second nonwoven being extensible, but inelastic, said second
nonwoven being further characterized by a CD/MD elongation ratio of
at least 3:1, said second nonwoven being a point-bonded carded
nonwoven made of staple fibers or a spunlaced nonwoven, a first
elastic film and a second elastic film, said first elastic film and
said second elastic film being laterally spaced apart from one
another and sandwiched between said first nonwoven and said second
nonwoven, said first elastic film and said second elastic film
being bonded to said first nonwoven and said second nonwoven,
respectively, by a plurality of continuous lines of a hot melt
adhesive extending in the MD direction when said first elastic film
and said second elastic film being non-tensioned, a non-extensible
material between said first elastic film and said second elastic
film and being sandwiched between and bonded to said first nonwoven
and said second nonwoven, whereby when the elastic composite is
stretched in the CD direction, said nonwovens extend with said
elastic films and when the elastic composite is relaxed, said
nonwovens bulk.
15. The elastic composite of claim 14 wherein said CD/MD elongation
ratio being in the range of 4-5:1.
16. The elastic composite according to claim 14 wherein said first
nonwoven or said second nonwoven being a spunlaced nonwoven.
17. The elastic composite according to claim 14 wherein said first
elastic film or said second elastic film or both comprising a
styrenic block co-polymer.
18. The elastic composite according to claim 14 wherein said first
elastic film or said second elastic film or both having a basis
weight in the range of 50-70 g/m.sup.2.
19. The elastic composite according to claim 14 wherein said hot
melt adhesive being a non-elastic adhesive.
20. The elastic composite according to claim 14 wherein a line of
said plurality of continuous lines having a width in the range of
0.5-1.0 mm.
21. The elastic composite according to claim 14 wherein a line of
said plurality of continuous lines having a width in the range of
0.5-0.55 mm.
22. The elastic composite according to claim 14 wherein a
center-to-center spacing of said plurality of continuous lines
being in the range of 2.0-2.5 mm.
23. The elastic composite according to claim 14 wherein said
non-extensible material between said first elastic film and said
second elastic film and being sandwiched between said first
nonwoven and said second nonwoven and bonded to said first nonwoven
and said second nonwoven with a hot melt adhesive.
Description
RELATED APPLICATIONS
[0001] This divisional application claims the benefit of co-pending
application Ser. No. 11/840,407 filed Aug. 17, 2007 which, in turn,
claimed the benefit of earlier-filed, co-pending U.S. Provisional
application Nos. 60/839,998 filed Aug. 24, 2006 and 60/889,311
filed Feb. 12, 2007.
FIELD OF THE INVENTION
[0002] The instant invention is directed to an elastic composite
for use in disposable garments, particularly as a side panel (or
ear) or a tab of a disposable diaper.
BACKGROUND OF THE INVENTION
[0003] Disposable garments, for example diapers or training pants,
are known. Such garments may have side panels (or ears) and/or
tabs. The side panels and/or tabs may be made from elastic
composites. Elastic composites typically comprise various
combinations of nonwovens and elastic materials, each combination
designed to obtain a specific solution to a particular problem.
Often, these elastic composites require some type of mechanical
work to activate the composite.
[0004] Examples of elastic composites (also known as elastic
laminates) may be found in U.S. Pat. Nos. 6,255,236 and 6,726,983.
U.S. Pat. No. 6,255,236 discloses an elastic laminate where two
nonwovens sandwich an elastic web, and the laminate has at least
one elastic lane and at least one stiffened lane. U.S. Pat. No.
6,726,983 discloses an elastic laminate where two nonwovens
sandwich an elastic film, and the elastic film is extrusion coated
onto one nonwoven and is thermally bonded to the other
nonwoven.
[0005] There is an on-going effort in the disposable garment
industry to provide new elastic composites with a balance of
physical and esthetic properties and cost. Accordingly, there is a
need for new elastic composites.
SUMMARY OF THE INVENTION
[0006] An elastic composite includes a first nonwoven, a second
nonwoven, and two elastic films sandwiched between the first and
second nonwovens. The elastic composite also includes a lateral
edge portion where the first nonwoven is bonded to the second
nonwoven, a lane between the elastic films that is free of the
elastic films, and a first bond joining the first nonwoven to the
elastic films, and a second bond joining the second nonwoven to the
elastic films. The elastic composite may be used as a component of
a disposable garment.
DESCRIPTION OF THE DRAWINGS
[0007] For the purpose of illustrating the invention, there is
shown in the drawings a form that is presently preferred; it being
understood, however, that this invention is not limited to the
precise arrangements and instrumentalities shown.
[0008] FIG. 1 is a schematic illustration of a representative
disposable garment, e.g., a diaper.
[0009] FIG. 2 is a schematic illustration of a second
representative disposable garment, e.g., a diaper.
[0010] FIG. 3 is a top plan view of an embodiment of the instant
invention, parts broken away for clarity.
[0011] FIG. 4 is an exploded sectional view of a first embodiment
of the instant invention taken along sectional lines A-A of FIG.
3.
[0012] FIG. 5 is an exploded sectional view of a second embodiment
of the instant invention taken along sectional lines A-A of FIG.
3.
[0013] FIG. 6 is an exploded sectional view of a third embodiment
of the instant invention taken along sectional lines A-A of FIG.
3.
[0014] FIG. 7 is an exploded sectional view of a fourth embodiment
of the instant invention taken along sectional lines A-A of FIG.
3.
[0015] FIG. 8 is an exploded sectional view of a fifth embodiment
of the instant invention taken along sectional lines A-A of FIG.
3.
[0016] FIG. 9 is a schematic illustration of a process for making
the instant invention.
DESCRIPTION OF THE INVENTION
[0017] Referring to the drawings, wherein like elements have like
numerals, there is shown in FIGS. 1 and 2 representative disposable
garments, diapers 10 and 30.
[0018] In FIG. 1, diaper 10 generally comprises a rear waist
portion 12, a front waist portion 14, and an interconnecting
portion 16. At the lateral edges of the rear waist portion 12,
there are affixed side panels (or ears) 18. At the distal ends of
the side panels 18, tabs 20 may be affixed thereto. At the distal
ends of tab 20, fastening device 22 may be affixed thereto. On the
exterior surface of front waist portion 14, a mating fastening
device 24 may be disposed (shown as two elements, but may be a
continuous element). Fastening device 22 and mating fastening
device 24 co-operate to releasably secure diaper 10 about a wearer,
as is well known. Fastening device 22 and mating fastening device
24 may be any known fastening mechanism. Such known fastening
mechanisms include, but are not limited to, hook and loop fasteners
and adhesive fasteners. In diaper 10, side panels 18 may be elastic
(e.g., stretchable in a direction away from rear waist portion 12),
so that the diaper may be securely fit to the wearer, and tabs 20
may be non-elastic.
[0019] In FIG. 2, diaper 30 generally comprises a rear waist
portion 32, a front waist portion 34, and an interconnecting
portion 36. At the lateral edges of the rear waist portion 32,
there are affixed side panels (or ears) 38. At the distal ends of
the side panels 38, tabs 40 may be affixed thereto. At the distal
ends of tab 40, fastening device 42 may be affixed thereto. On the
exterior surface of front waist portion 34, a mating fastening
device 44 may be disposed (shown as two elements, but may be a
continuous element). Fastening device 42 and mating fastening
device 44 co-operate to releasably secure diaper 30 about a wearer,
as is well known. Fastening device 42 and mating fastening device
44 may be any known fastening mechanism. Such known fastening
mechanisms include, but are not limited to, hook and loop fasteners
and adhesive fasteners. In diaper 30, side panels 18 may be
non-elastic, and tabs 20 may be elastic (e.g., stretchable in a
direction away from rear waist portion 32), so that the diaper may
be securely fit to the wearer.
[0020] Referring to FIG. 3, the instant invention, an elastic
composite 50, is shown. Elastic composite 50 generally comprises a
first (or bottom) nonwoven 54, a second (or upper) nonwoven 56, and
a first (or right) elastic film 58 and second (or left) elastic
film 60 sandwiched between the first nonwoven 54 and second
nonwoven 56. The elastic composite 50 generally comprises two
lateral edge portions 62, two stretch zones 64 and a lane 66 (lane
66 is divided by a center line 52 which is shown for reference). In
the lateral edge portion 62, the first nonwoven 54 and the second
nonwoven 56 may be bonded together (discussed in greater detail
below). In the stretch zone 64, the first and second nonwovens 54,
56 may be bonded to the upper and lower surfaces of the elastic
films 58, 60 (discussed in greater detail below).
[0021] The first and second nonwovens 54, 56 may be identical
materials. These nonwovens may be any nonwoven. In one embodiment,
the nonwoven has a basis weight in the range of 10-40 g/m.sup.2,
and in another embodiment, in the range of 22-30 g/m.sup.2. The
nonwoven, in one embodiment, is inelastic and highly extensible in
the cross machine direction (CD). In one embodiment, the nonwoven
has a CD extension at peak load of at least 200%. These nonwovens
may be further characterized, in another embodiment, by their CD/MD
(CD-cross machine or transverse direction; MD-machine direction)
elongation ratio which may be at least 1:1, or at least 3:1, or in
the range of 3-6:1, or in the range of 4-5:1. In one embodiment,
the nonwoven is a point-bonded, carded nonwoven or spunlaced
nonwoven produced from staple fibers. The staple fibers may be any
material, for example, polyester (e.g., PET), polyolefin (e.g.,
PP), or a blend of both. The nonwoven may have apertures. An
example of the point-bonded carded nonwoven is FPN 571D available
from Fiberweb of Simpsonville, S.C. or SAWABOND 4132 (22 g/m.sup.2)
from Sandler AG of Schwarzenbach, Germany. An example of the
spunlaced nonwoven is SAWATEX.RTM. 2628 available from Sandler AG
of Schwarzenbach, Germany.
[0022] The elastic films 58, 60 are, in one embodiment, identical
to one another. The elastic films may be made from any elastomeric
polymer. In one embodiment, the elastomeric polymers may be
styrenic block copolymers. Styrenic block copolymers include, but
are not limited to, SIS (styrene-isoprene-styrene) block
copolymers, SBS (styrene-butene-styrene) block copolymers, and
combinations thereof. The elastic film may have a basis weight, in
one embodiment, of 40-100 g/m.sup.2, and in another, 50-70
g/m.sup.2. The elastic film may be further characterized by CD
elongation of at least 200%.
[0023] The adhesive used in the bonding discussed above may be any
adhesive. In one embodiment, the adhesive is a hot melt,
non-elastic adhesive. Alternatively, adhesive may be replaced with
bonding (e.g., thermal, ultrasonic, and/or infrared with or without
binder fibers in the nonwoven).
[0024] The instant invention, elastic composite 50, shall be
discussed in further detail below with regard to the embodiments
shown in FIGS. 4-8.
[0025] In FIG. 4, elastic composite 50' is shown. In lateral edge
portions 62, the first nonwoven 54 and the second nonwoven 56 are
bonded together via lateral edge bonds 68. The lateral edge bonds
68 are formed from the adhesive discussed above. While in each
lateral edge portion 62 there is shown two layers of adhesive
(forming bonds 68), the invention is not so limited and, for
example, a single layer of adhesive (applied to either nonwoven)
may be used. Lateral edge bonds 68, in one embodiment, may be a
continuous layer of adhesive (i.e., the adhesive covers the length
and width of the lateral edge portions), whereby the nonwovens,
which are inelastic but extensible, are generally fixed (i.e.,
prevented or substantially prevented from extension). Lateral edge
bonds 68, in another embodiment, may be in the form of a grid or
cross-hatching of lines of adhesive, or any other pattern intended
to generally fix the nonwovens in the lateral edge portions 62. In
one embodiment where the width of the elastic composite is 170 mm,
the adhesive weight of the lateral edge bonds 68 is 8-9
g/m.sup.2.
[0026] Likewise, in lane 66, the first nonwoven 54 and the second
nonwoven 56 are bonded together via lane bonds 72. The lane bonds
72 are formed from the adhesive discussed above. While in lane 66
there is shown two layers of adhesive (forming bonds 72), the
invention is not so limited and, for example, a single layer of
adhesive (applied to either nonwoven) may be used. Lane bonds 72,
in one embodiment, may be a continuous layer of adhesive (i.e., the
adhesive covers the length and width of the lane), whereby the
nonwovens, which are inelastic but extensible, are generally fixed
(i.e., prevented or substantially prevented from extension). Lane
bonds 72, in another embodiment, may be in the form of a grid or
cross-hatching of lines of adhesive, or any other pattern intended
to generally fix the nonwovens in the lane portion 66. In one
embodiment where the width of the elastic composite is 170 mm, the
adhesive weight of the lane bond 78 is 2-3.2 g/m.sup.2.
[0027] In stretch zones 64, the first nonwoven 54 and the second
nonwoven 56 are bonded to elastic films 58, 60 via stretch zone
bonds 70. The stretch zone bonds 70 are located between the first
nonwoven 54 and the elastic films 58, 60, and between the second
nonwoven 56 and the elastic films 58, 60, as shown. The stretch
zone bonds 70 are formed from the adhesive discussed above. The
stretch zone bond 70 consists of a plurality of adhesive bonds,
whereby when the elastic composite is stretched in the CD, the
nonwoven may extend with the elastic film, and when the elastic
composite is relaxed, the nonwoven may bulk. The stretch zone bonds
70, in one embodiment, may be a plurality of continuous lines of
adhesive extending in the MD (in the drawing, this is illustrated
by a horizontal line of dots). The stretch zone bond 70, in another
embodiment, may be a plurality of discontinuous (e.g., dots) lines
of adhesive extending in the MD (in the drawing, this is
illustrated by a horizontal line of dots). The elastic films 58, 60
may extend to the lateral edges of the stretch zone 64 or may
extend slightly over the lateral edges of the stretch zone 64.
Instead of lines of adhesive, a continuous film of adhesive of
various weights/volumes/densities of adhesives may be used (e.g., a
pattern of high density adhesive lines with lower densities there
between). In one embodiment, the lines of adhesive may have a width
in the range of 0.5-1.0 mm or 0.5-0.55 mm. In one embodiment, the
center-to-center line of adhesive spacing may be in the range of
2.0-2.5 mm.
[0028] In FIG. 5, elastic composite 50'' is shown. Elastic
composite 50'' is the same as elastic composite 50' (of FIG. 4),
except as follows. A stiffener 74 is added to lane 66 between the
first nonwoven 54 and the second nonwoven 56. Stiffener 74 is added
to provide additional mechanical strength to lane 66. Lane 66 may
be the portion of the elastic composite that is affixed to the
disposable garment or the fastener may be affixed thereto, and as
such may require additional mechanical strength to facilitate
attachment to the garment in assembly of the garment and/or use of
the garment. Stiffener 74 is bonded to the first nonwoven 54 and
the second nonwoven 56 via lane bonds 72, as discussed above.
Stiffener 74 is a non-extensible material (non-extensible with
regard to the elastic films 58, 60). Stiffener 74 may be a film or
nonwoven. In elastic composite 50'', stiffener 74 extends slightly
beyond the lateral edges of lane 66 and overlaps (but may not be
bonded thereto) the elastic films 58, 60.
[0029] In FIG. 6, elastic composite 50''' is shown. Elastic
composite 50''' is the same as elastic composite 50'' (of FIG. 5),
except as follows. Stiffener 74 does not overlap elastic films 58,
60, and when the elastic composite 50''' is assembled, the lateral
edges of stiffener 74 are adjacent to or abut with their respective
lateral edge of the elastic films.
[0030] In FIG. 7, elastic composite 50'''' is shown. Elastic
composite 50'''' is the same as elastic composite 50' (of FIG. 4),
except as follows. In elastic composite 50'''', elastic films 58,
60 are replaced with film 76. Film 76 has three zones, two lateral
stretch portions 78 (corresponding to the stretch zones 64) and a
center portion 80 therebetween (corresponding to lane 66). The
lateral stretch portions 78 are elastic and the center portion 80
is inelastic. Film 76 is a unitary material and may be made by
co-extrusion.
[0031] In FIG. 8, elastic composite 50A is shown. Elastic composite
50A is similar to the foregoing elastic composites, except as
follows. Elastic composite 50A has no lane 66. Instead, elastic
composite 50A includes elastic film 82 (same materials of
construction as prior elastic films) which may be adhered to the
first nonwoven 54 and second nonwoven 56 via stretch zone bonds 70,
as shown. Elastic composite 50A consists of two lateral edge
portions 62 and an intermediate stretch zone 64.
[0032] Referring to FIG. 9, a process 100 for making elastic
composite 50 is illustrated. In extrusion step 102, the elastic
films 58, 60 or film 76 is made from polymeric resins in to the
extruded material. In cooling step 104, the extruded material is
cooled and solidified. In laminating step 106, elastic films 58, 60
or film 76 (and/or stiffener 74 as needed) are laminated between
nonwovens 54, 56 (nonwovens 54, 56 being provided from supplies
108). Typically, there is no tension in the laminator (except for
the slight tensions necessary to move the films and nonwovens
therethrough). Optionally, however, a tension (in the MD) may be
added to `neck down` the nonwoven prior to lamination to the film.
In stiffening step 110, lane 66 (and/or lateral edge portions 62)
may be subject to calendering (either heated or nonheated rollers)
to ensure firm bonding therein. Finally, in take-up step 112, the
elastic composite 50 may be subjected to inspection, edge trim,
winding up, and/or packaging.
[0033] When used in the disposable garment, the elastic composite
may be cut along center line 52; so that one portion may be used on
the right side of the garment and the other portion may be used on
the left side of the garment. When elastic composite 50 is used as
a side panel (or ear), the elastic composite should have a CD
elongation of at least 140%. When the elastic composite 50 is used
as a tab, the elastic composite should have a CD elongation of at
least 35% (to obtain this elongation, it may be necessary to use a
continuous adhesive layer for stretch zone bonds 70). The lane
portion of the elastic composite is used to fasten the elastic
composite to the garment.
[0034] The present invention may be embodied in other forms without
departing from the spirit and the essential attributes thereof,
and, accordingly, reference should be made to the appended claims,
rather than to the foregoing specification, as indicated the scope
of the invention.
* * * * *