U.S. patent application number 10/420470 was filed with the patent office on 2004-10-28 for stretch fabric.
This patent application is currently assigned to Andover Coated Products, Inc.. Invention is credited to Murphy, Thomas S., Piaseczynski, Stanley J..
Application Number | 20040214494 10/420470 |
Document ID | / |
Family ID | 33298511 |
Filed Date | 2004-10-28 |
United States Patent
Application |
20040214494 |
Kind Code |
A1 |
Murphy, Thomas S. ; et
al. |
October 28, 2004 |
Stretch fabric
Abstract
A laminated elastic fabric includes a first carrier layer of
non-elastic, open fabric, and a second layer which is elastic in a
direction extending longitudinally of the fabric; a first outer
fabric layer and a second outer fabric layer on opposing sides of
the first carrier and second elastic layers, and a binder bonding
the layers together. The carrier layer can be a warp knit/weft
insertion fabric having knit yarns and fill yarns and oriented with
the knit yarns thereof extending longitudinally of the fabric, the
knit yarns being non-elastic, each of the knit yarns extending
longitudinally of the fabric including a plurality of
longitudinally-spaced knitted loops, and each of the fill yarns
extending transversely of the fabric and through loops of the knit
yarns.
Inventors: |
Murphy, Thomas S.; (Bedford,
MA) ; Piaseczynski, Stanley J.; (Epping, NH) |
Correspondence
Address: |
WILMER CUTLER PICKERING HALE AND DORR LLP
60 STATE STREET
BOSTON
MA
02109
US
|
Assignee: |
Andover Coated Products,
Inc.
Salisbury
MA
|
Family ID: |
33298511 |
Appl. No.: |
10/420470 |
Filed: |
April 22, 2003 |
Current U.S.
Class: |
442/149 ; 442/10;
442/2; 442/312; 442/313; 442/314; 442/50 |
Current CPC
Class: |
Y10T 442/102 20150401;
Y10T 442/116 20150401; Y10T 442/184 20150401; D04B 21/18 20130101;
Y10T 442/45 20150401; D04B 21/16 20130101; Y10T 442/456 20150401;
Y10T 442/2738 20150401; Y10T 442/463 20150401 |
Class at
Publication: |
442/149 ;
442/002; 442/010; 442/050; 442/312; 442/313; 442/314 |
International
Class: |
D04B 001/00; D04B
011/10 |
Claims
What is claimed is:
1. A elastic fabric comprising: a first carrier layer of a
non-elastic, open fabric; a second layer, which is elastic in a
direction extending longitudinally of the fabric; a first outer
fabric layer and a second outer fabric layer on opposing sides of
the first carrier and second elastic layers; and a binder bonding
the layers together.
2. The elastic fabric of claim 1, wherein the carrier fabric
comprises a warp knit/weft insertion fabric having knit yarns and
fill yarns and oriented with the knit yarns thereof extending
longitudinally of the fabric, said knit yarns being non-elastic,
each of said knit yarns extending longitudinally of the tape and
including a plurality of longitudinally-spaced knitted loops, and
each of the fill yarns extending transversely of the fabric and
through loops of the knit yarns.
3. The elastic fabric of claim 1, wherein the carrier layer is
selected from the group consisting of woven, nonwoven, warp
knit/weft insertion and knitted fabrics.
4. The fabric of claim 1 or 2, wherein the binder is in adhesive
contact with all layers of the fabric.
5. The fabric of claim 1 or 2, wherein the binder impregnates the
first carrier layer and coats the second elastic layer.
6. The fabric of claim 5, wherein the binder penetrates a partial
thickness of the first and second outer layers.
7. The fabric of claim 5, wherein the binder penetrates up to about
95% of the thickness of the first and second outer layers.
8. The fabric of claim 5, wherein the binder penetrates in the
range of about 25% to about 75% of the thickness of the first and
second outer layers.
9. The fabric of claim 5, wherein the binder penetrates up to 50%
of the thickness of the first and second outer layers.
10. The fabric of claim 1, wherein the top and bottom outer layers
are selected from the group consisting of nonwoven materials, woven
materials, knitted materials, and warp knit/weft insertion
fabrics.
11. The fabric of claim 10 wherein said nonwoven is selected from
the group consisting of nylon, rayon, cellulosics, cotton,
polyester, polyamide, acrylics, polyethylene, and
polypropylene.
12. The fabric of claim 1, wherein said second layer comprises
individual elastic strands spaced transversely of the fabric
relative to each other and extending longitudinally of the
fabric.
13. The fabric of claim 12, wherein said elastic strands have a
denier less than about 1000.
14. The fabric of claim 12, wherein said elastic strands are spaced
at a density in the range of 5 to 15 per inch measured transversely
of the bandage.
15. The fabric of claim 2, wherein the knit yarns of the warp
knit/weft insert fabric comprises polyester.
16. The fabric of claim 2, wherein the fill yarns of the warp
knit/weft insertion fabric comprise a plurality of yarns.
17. The fabric of claim 1 or 2, wherein the carrier fabric has an
openness of up to about 95%.
18. The fabric of claim 1 or 2, wherein the carrier fabric has an
openness of up to about 70%.
19. The fabric of claim 1, wherein the binder comprises a
self-curing adhesive.
20. The fabric of claim 1, wherein the binder is a thermosetting
adhesive.
21. The fabric of claim 1, wherein the binder is a thermoplastic
adhesive.
Description
FIELD OF THE INVENTION
[0001] This invention relates to a composite material with
controlled elasticity. More particularly, the invention relates to
stretch fabrics having an elastic layer laminated to an open
carrier layer.
BACKGROUND OF THE INVENTION
[0002] Various kinds of sheet materials having flexibility,
elasticity or resiliency have been used for producing the elastic
portions of sportswear, clothes for working and surgical
operations, working gloves, gathers of caps and hats, diapers,
suspenders, belts and the like. In the past, elastic materials have
been made elastically extensible using elastic elements disposed,
e.g., woven, in the clothes such that the openings are at least
partially encircled with elasticized bands. Still other methods
include attaching stretchable fabric to the side edges of the main
body of the garment. The stretchable fabric can be made by
stretching an elastic or stretchable layer to a selected
elongation, placing a nonstretchable layer, such as a nonwoven on
the stretched layer, bonding the layers together and allowing the
layers to relax so that the nonstretchable layer is gathered.
[0003] There remains a need for an inexpensive, elastic fabric that
has a good appearance, is soft and comfortable to wear and that,
despite its low cost, has a high longitudinal strength.
SUMMARY OF THE INVENTION
[0004] The present invention features a stretch fabric including a
layer that is elastic in the longitudinally extending direction
laminated to one side of a carrier layer. The elastic layer/carrier
layer laminate is sandwiched between and bonded to top and bottom
outer fabric layers that impart the desired properties of
appearance, softness and comfort to the elastic fabric.
[0005] In one or more embodiments, the elastic layer is a plurality
of longitudinally-extending elastic strands. In one or more
embodiments, the carrier layer is a warp-knitted fabric, also
referred to as a warp knit/weft insertion fabric, oriented with the
knit yarns extending longitudinally. The warp knit/weft insertion
fabric has a weight of less than about 50 grams per square meter
(about 1.5 oz. per square yard) and most preferably less than about
25 to 30 grams per square meter (about 0.7 to 0.9 oz. per square
yard). The top and bottom outer layers can be a lightweight
spun-blown synthetic or natural fiber nonwoven, a knitted, or a
woven fabric.
[0006] The stretch fabric has a good appearance and is soft and
comfortable to the touch, yet has 2a longitudinal strength and is
less expensive than its woven or knitted competitors where the
elastic yarns are woven or knitted into the fabric as an integral
part of the woven or knitted cloth.
BRIEF DESCRIPTION OF THE DRAWINGS
[0007] FIG. 1 is top view, partially broken away, of a stretch
fabric according to one or more embodiments of the present
invention.
[0008] FIG. 2 is a cross-sectional view, taken at line 2--2 of FIG.
1.
[0009] FIG. 3 is a top view of a warp knit/weft insertion layer for
use in one or more embodiments of the present invention.
DETAILED DESCRIPTION OF THE INVENTION
[0010] FIGS. 1 and 2 illustrate a laminated elastic fabric 10
having a top layer 12 and a bottom layer 14 of an outermost woven,
knit or nonwoven fabric that imparts the desired properties of
appearance, softness and comfort to the fabric. Positioned between
the top and bottom layers is a carrier layer 16, shown here as a
warp knit/weft insertion fabric, and an elastic layer 18 of
longitudinally-extending, transversely spaced (about 12 per inch)
elastic strands. The four-layer structure is laminated together
with a binder 20 that impregnates the inner warp knit/weft
insertion fabric, coats the elastic layer, and penetrates into a
portion of the top and bottom outer layers.
[0011] The adhesive does not saturate the full thickness of the top
and bottom outer layers, so that the outermost surface of the
elastic fabric is essentially free of binder. The binder can
penetrate up to about 95% of the thickness of outer layers, and in
some embodiments, the binder penetrates into about 25% to about 75%
of the outermost fabric. Typically, the binder penetrates into
about 50% of the outermost fabric.
[0012] The outermost fabric contacts the wearer and, as such, is a
fabric that is comfortable and provides a pleasing appearance.
There is no requirement of a particular weight, weave or thickness
for the outer layer. The top and bottom layers can be the same or
different. In some embodiments, it is breathable and/or capable of
gathering. The outer fabric is a woven, knit, weft knit/warp
insertion or nonwoven fabric prepared from synthetic or natural
fibers. For example, they may be selected from the naturally
occurring animal and vegetable fibers, including cotton and wool,
or synthetic (chemical) fibers such as nylon, cellulosics, rayon,
polyesters, polyamides, acrylics, polypropylene, polyethylene and
the like, including blends of such fibers. In a nonwoven substrate
backing, the fibers are intimately entangled with each other to
form a coherent breathable fibrous nonwoven backing. The particular
fiber composition that is used as the nonwoven backing substrate is
selected from those known in the prior art, according to the web
property desired. Exemplary nonwovens having a desirable soft or
comfortable feel include polypropylene, polyester, polyethylene,
and cotton nonwovens. In one or more embodiments, the nonwoven
fabric is lightweight, and can typically be about 10 grams per
square meter (about 0.3 oz. per square yard) or about 17-20 grams
per square meter (about 0.5-0.6 oz. per square yard).
[0013] The carrier layer supports the elastic layer and acts as a
carrier for the binder. The carrier layer can be any lightweight
and open woven, knit or nonwoven fabric, or it can be a warp
knit/weft insertion fabric. The carrier layer is selected to
reinforce the assembled structure, while retaining the openness
(which is a function of thread count and yarn denier, etc.) of the
fabric. It is also selected to provide sufficient adhesive surface
area to establish a strong adhesive contact with the outer fabric
layers and the elastic layer. The fabric can be up to about 95%
open, i.e., the fabric makes up about 5% of the surface area, and
is typically about 70% open.
[0014] Referring to FIG. 3, a warp knit/weft insertion fabric 300
is shown on outer fabric 310. The warp-knit/weft insertion fabric
300 includes one or more weft yarns 320 inserted through a knit
loop 325. The weft insert yarns may include one or more filaments,
the number and size of which are selected to have a desired tensile
strength. By way of example only, the weft yarns are shown having
three filaments; however, the weft yarns may be monofilament or
multifilament, for example, the weft yarns can have a number of
filaments, for example, 3-15 filaments. Because the fabric is warp
knit/weft insertion rather than conventionally woven, the knitted
warp yarns 325 form rather loose warp yarn "loops" around the fill
yarns 320, and the knitted warp structure also provides that each
row of the knitted warp includes three yarns extending in the warp
direction. This three-yarn warp knit/weft insertion construction
results in a lightweight fabric having high tensile strength (about
12.8 lbs/inch) in the warp direction.
[0015] The fully extended warp knit/weft insertion fabric 300
includes spaces 330 between adjacent weft yarns 320. This spacing,
coupled with the loose, non-twisted, filamentary structure of the
weft yarns themselves, permits the weft yarns to move towards and
away from each other in response to stretch and relaxation of the
longitudinal elastic strands 18, which is of course accompanied by
elongation and relaxation of the warp yarns.
[0016] In one or more embodiments, the warp knit/weft insertion
fabric has a weight of less than about 50 grams per square meter
(about 1.5 oz. per square yard) and most preferably less than about
25 to 30 grams per square meter (about 0.7 to 0.9 oz. per square
yard), and may be as low as 5 grams per square meter. An exemplary
warp knit/weft insertion fabric has a weight ranging from about 25
to about 10 grams per square meter, and a warp/weft thread count
ranging from about 18.times.12 to about 9.times.9. The knitted warp
yarns are about 40 denier polyester; the about 150 denier fill or
weft yarns are loose, nontwisted, texturized polyester filaments.
Similar warp knit/weft insertion fabrics are available elsewhere,
e.g., warp knit/weft insertion greige fabric available from
Milliken & Company of Spartenburg, S.C. A lightweight fabric
maintains the porosity of the stretch fabric and relaxes to a
smooth, comfortable gather.
[0017] The elastic strands 18 used in the present invention for the
elastic layer include thermoplastic elastomers, synthetic and
natural rubbers. An exemplary elastic strand is a 280 denier
strand, which is sold under the trademark GLOSPAN by Radici spandex
Inc. of Fall River, Mass. Depending on the amount of elasticity
desired in the elastic fabric 10, both the denier and number of
elastic strands per inch (measured transversely) of the fabric may
vary. For example, the denier of the elastic strands may vary from
less than 100 to about 1000, and there may be from about 5 to about
15 elastic strands per inch. In some embodiments, the elastic yarns
provide an elastic fabric having a degree of stretch (elongation)
ranging from approximately 40% to 275%.
[0018] Typically, the elastic fabric 10 is formed by laminating the
warp knit/weft insertion fabric 16 when fully extended or taut over
stretched elastic strands 18. The binder-impregnated elastic
layer/warp knit/weft insertion layer is then contacted, while still
fully extended, with the upper and lower outer layers. Binder 20
impregnates or coats the inner two layers and penetrates into a
portion of the top and bottom outer layers. The particular binder
20 used to laminate the four layers together to form the finished
product depends, principally, on whether and what kind of adhesive
properties are desired. The binder can be a thermosetting or
thermoplastic adhesive that remains flexible when set or cured.
Typically, the binder is a self-curing laminating adhesive.
Exemplary binders include carboxylated styrene butadiene (SBR)
latexes, acrylic emulsions, copolymer acrylic emulsions, and the
like.
[0019] An exemplary fabric includes a lightweight nonwoven
polypropylene top and bottom outer fabric having a weight of 10
g/m.sup.2. The carrier layer is a warp knit/weft insertion fabric
having a 9.times.12 warp/weft thread count with a 40 denier
monofilament polyester warp yarn and a multifilament warp yarn of
70 denier. The elastic layer is 280 denier spandex rubber. All four
layers are bonded together using Rovene.RTM. 4150 carboxylated SBR
emulsion. The resultant fabric has a strength in the longitudinal
warp direction of about 12 pounds per inch of width, yet it is
light and comfortable to wear. As compared to the commercially
available elastic fabrics made by weaving or knitting elastic yarns
into a woven fabric, the laminated elastic fabric of the present
invention provides a feel and an appearance that is at least equal
and often superior to comparable elastic fabrics.
[0020] The foregoing detailed description includes many specific
details. The inclusion of such detail is for the purpose of
illustration only and is non-limiting of the invention. In
addition, features in one embodiment may be combined with features
in other embodiments of the invention. Various changes may be made
without departing from the spirit and scope of the invention as
defined in the following claims.
* * * * *