Note: Descriptions are shown in the official language in which they were submitted.
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FIELD OF THE INVENTION
The present invention relates to composite elastic
materials and a method of making the same.
BACKGROUND OF THE INVENTION
There has been a continuing need for pile fabrics and
lanate materials having a high degree of flexibility,
elasticity, bulk and strength and which may be manufactured
at a low cost. This need has persisted in spite of the
fact that such fabrics could readily be utilized to
manufacture a wide variety of garments of both. the
disposable type, such as disposable work wear and
disposable diapers, or the durable type, such as pants,
dresses, blouses and sporting wear, for example, sweat
suits. Further, such fabrics could also be utilized in,
for example, upholstery, drapery, and liner applications.
Lanate materials have a woolly or fleecy structure which
may be particularly well suited in applications where
insulation properties are desired.
In some situations, the value of the pile fabric or
lanate material relates to the density at which the fibrous
materials are attached to the substrate as well as the
overall flexibility and elasticity of the material. Pile
fabrics and lanate materials having high densities of
fibrous materials typically have richer surface textures
and greater market value.
Pile fabrics and lanate materials may be formed by
attaching fibrous materials such as, for example, fibers or
fiber bundles to a substrate. Fibers may be inserted into
a substrate utilizing processes such as, for example,
mechanical needling. In same situations, pile fabrics may
be formed by adhering fibers onto the surface of a
substrate utilizing flocking techniques. Pile fabrics and
lanate materials may also be formed by tufting or
stitchbonding fiber bundles, such as, for example, yarns or
threads into a substrate.
While pile fabrics and lanate materials having a high
density of attached fibrous materials often have a pleasing
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surface appearance and feel, such fabrics may be so stiff
so that the fabric is unsuitable for applications where
flexibility and suppleness are desirable. For example,
fabrics that are stiff and inflexible will conform poorly
to the body of a wearer or to an item and are unsuitable
for some apparel and upholstery applications.
When pile fabrics and lanate materials are made by
attaching fibrous materials to a substrate utilizing
mechanical needling, the density at which the fibrous
materials may be attached to the substrate is limited by
the distance between the mechanical needles. The density
at which the fibrous materials are attached to the
substrate may be increased by subjecting the fibrous
materials and substrates to multiple passes through the
mechanical needling apparatus. However, multiple passes
result in matted, highly entangled materials that, in most
situations, have low bulk and are essentially nonelastic.
Post entanglement stretching may be used .to return some
elasticity to such composites, but such stretching may
reduce the strength and durability of the composite
material.
An elastic laminate material may be made by
mechanically needling a coherent nonwoven web of textile
fibers to an elastic substrate only at spaced-apart
locations. One such laminate material is described in U.S.
Patent No. 4,446,189 to Romanek which discloses that a
nonwoven textile fabric layer and a layer of generally
elastic material are superposed and needlepunched to secure
the fabric layer to the layer of generally elastic material
3o at a plurality of needle punch locations each spaced a
predetermined distance from the next adjacent needle punch
location. The needle punched layers are drafted in at least
one direction to permanently stretch the nonwoven textile
fabric layer where it is not joined to the elastic layer.
The superposed layers are allowed to relax so the elastic
layer returns to substantially its original dimensions and
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the bulk of the stretched nonwoven textile fabric is
increased between the needle punched locations.
A hydroentangled elastic nonwoven fabric may be made by
stretching an elastic substrate in at least one direction
before the elastic substrate is hydraulically entangled
with a preformed fibrous web. A hydroentangled elastic
fabric is disclosed by U. S. Patent No. 4,775,579 to Hagy
et al. and may be prepared by stretching an elastic
fieltblown continuous filament web in at least one direction
prior to hydraulic entanglement with a preformed web of
wood pulp and absorbent staple length fibers.
DEFINITIONS
The term "elastic" is used herein to mean any material
which, upon application of a biasing force, is stretchable,
that is, elongatable, to a stretched, biased length which
is at least about 125 percent of its relaxed unbiased
length, and which, will recover at least 40 percent of its
elongation upon release of the stretching, elongating
force. A hypothetical example would be a one (1) inch
sample of a material which is elongatable to at least 1.25
inches and which, upon being elongated to 1.25 inches and
released, will recover to a length of not more than 1.15
inches. Many elastic materials may be stretched by much
more than 125 percent of their relaxed length, for example,
400 percent or more, and many of these will recover to
substantially their original relaxed length, for example,
to within 105 percent of their original relaxed length,
upon release of the stretching force.
As used herein, the term "nonelastic" refers to any
material which does not fall within the definition of
"elastic," above.
As used herein, the terms "recover" and "recovery"
refer to a contraction of a stretched material upon
termination of a biasing force following stretching of the
material by application of the biasing force. For example,
if a material having a relaxed, unbiased length of one (1)
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inch is elongated 50 percent by stretching to a length of
one and one half (1.5) inches, the material would be
elongated 50 percent (0.5 inch) and would have a stretched
length that is 150 percent of its relaxed length. If this
exemplary stretched material contracted, that is recovered
to a length of one and one tenth (1.1) inches after release
of the biasing and stretching force, the material would
have recovered 80 percent (0.4 inch) of its one-half (0.5)
inch elongation. Recovery may be expressed as [(maximum
stretch length - final sample length)/(maximum stretch
length - initial sample length)] X 100.
As used herein, the term "percent elongation" refers to
the relative increase in the length of an elastic material
during tensile testing. Percent elongation may be
determined utilizing tensile testing equipment such as, for
example, an Instron Model 1122 Universal Testing
Instrument. Percent elongation is expressed ratio of the
difference between the stretched length and the initial
length of a sample divided by the initial length of the
sample utilizing the following equation:
percent elonpetion ~ Iletretehed length ~ initial length>/Iinitiel
Length)1'100
As used herein, the term "nonwoven web" means a web
having a structure of individual fibers or threads which
are interlard, but not in an identifiable, repeating
manner. Nonwoven webs have been, in the past, formed by a
variety of processes such as, for example, meltblowing
processes, spunbonding processes and bonded carded web
processes.
As used herein, the term "sheet" means a layer which
may either be a film or a nonwoven web.
As used herein, the term "meltblown fibers" means
fibers formed by extruding a molten thermoplastic material
through a plurality of fine, usually circular, die
capillaries as molten threads or filaments into a high
velocity gas (e.g. air) stream which attenuates the
filaments of molten thermoplastic material to reduce their
diameter, which may be to microfiber diameter. Thereafter,
CA 02077247 1999-OS-07
the meltblown fibers are carried by the high velocity gas
stream and are deposited on a collecting surface to form a
web of randomly disbursed meltblown fibers. Such a process
is disclosed, for example, in U.S. Patent No. 3,849,241 to
5 Butin.
As used herein, the term "microfibers" means small
diameter fibers having an average diameter not greater than
about 100 microns, for example, having an average diameter
l0 of from about 0.5 microns to about~50 microns, or more
particularly, microfibers-may have an average diameter of
from about 4 microns to about 40 microns.
As used herein, the term "spunbonded fibers" refers to
small diameter fibers which are formed by extruding a
molten thermoplastic material as filaments from a plurality
of fine, usually circular, capillaries of a spinnerette
with the diameter of the extruded filaments then being
rapidly reduced as by, for example, eductive drawing or
other well-known spun-bonding mechanisms. The production
of spun-bonded nonwoven webs is illustrated in patents such
as, for example, in U.S. Patent No. 4,340,563 to Appel et
al., and U.S. Patent No. 3,692,618 to Dorschner et al.
As used herein, the term "increased pile density"
refers to a pile or collection of fibrous materials such as
fibers or fiber bundles that are attached to an elastic
sheet while the elastic sheet is stretched in at least one
direction so that, upon recovery of the elastic sheet, the
fibrous materials are positioned closer together than
before recovery of the elastic sheet. Upon recovery of the
elastic sheet, the fibrous materials are typically
positioned from about 10 percent to about 300 percent
closer together, for example, from about 25 to about 100
percent closer together than before recovery of the elastic
sheet. Factors that affect the positioning of the fibrous
materials closer together include, for example, the
6
elongation at which the elastic sheet is maintained while
the fibers or fiber bundles are attached to the elastic
sheet, the retractile force of the elastic sheet, the
physical proximity and/or size of the fibers or fiber
bundles attached to the elastic sheet, and the volume
occupied by any fibers or fiber bundles which are inserted
into the elastic sheet.
As used herein, the term "increased pile density
composite elastic material" refers to an elastic material
having at least one elastic sheet and fibrous materials
such as fibers (e.g., synthetic fibers, natural fibers, or
monofilament strands) or fiber bundles (e. g., yarns,
threads, or multifilament strands) projecting in a
substantially perpendicular direction from the elastic
sheet to form a pile of fibrous materials which may be in
the form of strands or loops that are substantially
parallel with one another. The elastic sheet and the
fibrous materials may be substantially united by inserting
the fibrous materials into the elastic sheet utilizing
stitchbonding, malipole stitchbonding, or tufting
techniques. Alternatively, the elastic sheet and the
fibrous materials may be substantially united by adhering
the fibrous materials onto the elastic sheet utilizing
processes such as, for example, electrostatic flocking to
produce a composite elastic material having an increased
pile density as described above.
As used herein, the term "lanate composite elastic
material" refers to an elastic material having at least one
elastic sheet and fibrous materials such as fibers (e. g.,
synthetic fibers, natural fibers, or monofilament strands)
or fiber bundles (e. g., yarns, threads, or multifilament
strands) inserted into the elastic sheet by mechanical
needling techniques to provide a woolly or fleece-like
material having stretch and recovery properties. Lanate
composite elastic materials also are drapable, bulky (e. g.,
low density) and have good insulation properties.
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As used herein, the term "superabsorbent" refers to
absorbent materials capable of absorbing at least 10 grams
of aqueous liquid (e. g. water) per gram of absorbent
material while immersed in the liquid for 4 hours and
holding the substantially all absorbed liquid while under
a compression force of up to about 1.5 psi.
As used herein, the term "polymer" generally includes,
but is not limited to, homopolymers, copolymers, such as,
for example, block, graft, random and alternating
copolymers, terpolymers, etc. and blends and modifications
thereof. Furthermore, unless otherwise specifically
limited, the term "polymer" shall include all possible
geometrical configurations of the material. These
configurations include, but are not limited to, isotactic,
syndiotactic and random symmetries.
As used herein, the term "consisting essentially of"
does not exclude the presence of additional materials which
do not significantly affect the desired characteristics of
a given composition or product. Exemplary materials of
this sort would include, without limitation, pigments,
antioxidants, solvents, stabilizers, surfactants, waxes,
flow promoters, particulates and materials added to enhance
processability of the composition.
SUriMARY OF THE INVENTION
The present invention addresses the problems discussed
above by providing both lanate composite elastic materials
and increased pile density composite elastic materials as
well as methods of making the same.
According to the present invention, the method of
making a lanate composite elastic material includes the
steps of applying a tensioning force to elongate at least
one elastic sheet; inserting substantially individualized
fibrous materials into the elastic sheet by mechanical
needling the elastic sheet while it is maintained in an
elongated condition; and releasing the tensioning force so
the afaached fibrous materials are positioned closer
8
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together by the recovery of the elastic sheet. The
resulting lanate composite elastic material has stretch and
recovery properties, bulk, and desirable insulation
properties.
In one aspect of the present invention, an increased
pile density composite elastic material is made by a method
which includes the' step of inserting substantially
individualized fibrous materials into an elongated elastic
sheet by stitchbonding, malipole stitchbonding, or tufting
or, alternatively, the step of adhering substantially
individualized fibrous materials to an elongated elastic
sheet by flocking techniques. The density of attached
fibrous materials in the resulting increased pile density
composite elastic material is greater than could be
achieved by conventional fiber insertion or adherence
techniques while still maintaining desirable elastic
properties, bulk, drape and conformability.
The present invention also contemplates multilayer
materials composed of at least one layer of a lanate
composite elastic material and/or increased pile density
composite elastic material and at least one other layer of
material.
Generally speaking the elastic sheet, such as, for
example, an elastic nonwoven web, should be elongated at
least about 15 percent, for example, from about 20 to about
400 percent and maintained in that elongated condition
while the individualized fibrous materials, such as, for
example, a carded batt of staple fibers are attached to the
elastic sheet. Additional attachaent between the inserted
fibrous materials and the elastic sheet may be achieved by
using a pressure sensitive adhesive elastic sheet or by
using a thermal binder. The thermal binder may be in the
form of bi-component or multi-component fibers having a
low-melting sheath and a high-melting core, or a blend of
low-and high-melting fibers. The thermal binder may be
used in the elastic sheet or in both the fibrous materials
and the elastic sheet.
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The elastic sheet may be an elastic film or an elastic
nonwoven web of fibers such as, for example, an elastic
bonded carded web, an elastic spunbonded web, or an elastic,
web of meltblown fibers. If the elastic nonwoven web
coni:.ains meltblown fibers, the meltblown fibers may include
meltblown microfibers. The elastic nonwoven web may have
multiple layers such as, for example, multiple spunbond
layers and/or multiple meltblown layers.
The elastic sheet may be made of an elastic polymer
selected from, for example, elastic polyesters, elastic
polyurethanes, elastic polyamides, elastic copolymers of
ethylene and at least one vinyl monomer, and elastic AB
A' block copolymers wherein A and A' are the same or
different thermoplastic polymer, and wherein B is an
elastomeric polymer block. A polyolefin may also be blended
with the elastomeric polymer to improve the processability
of the composition when the elastic sheet is made using
nonwoven extrusion processes. Polyolefins which may be
blended with the elastomeric polymer include, for example,
polyethylene, polypropylene and polybutylene, including
ethylene copolymers, propylene copolymers and butylene
copolymers. Other substances may be used in addition to or
in place of a polyolefin (e. g., a low molecular weight
hydrocarbon resin and/or a mineral oil).
The individualized fibrous materials may be nonelastic
fibers or nonelastic fiber bundles. The fibers may be in
the form of an un-bonded web or batt of individualized
fibers, such as, for example, a carded batt of staple
fibers or a web of loose meltblown fibers. Useful staple
fibers have a denier, for example, from about 0.5 to about
20 and an average length, for example, from about ~ inch to
about 6 inches. If the fibrous materials are fiber
bundles, they may be, for example, threads, yarns, or
multifilament strands.
The fibrous materials may be natural fibers, such as,
for example, plant, animal or mineral fibers. For example,
the fibrous materials may be cotton, wool, or glass fibers.
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The fibrous materials may also be man-made fibers, such as,
for example, reconstituted cellulose or synthetic polymer
fibers including, for example, fibers formed from nylon,
polyester, polypropylene, polyethylene, polybutylene,
5 polyethylene copolymers, polypropylene copolymers, and
polybutylene copolymers.
In one aspect of the present invention, at least one
layer of the lanate composite elastic material and/or the
increased pile density composite elastic material may be
l0 combined with at least one other layer of material to form
a multilayer material.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 ,is a schematic representation of an exemplary
process for making the materials of the present invention.
DETAILED DESCRIPTION OF THE INVENTION
Referring to the drawings where like reference numerals
represent like materials or process steps and, in part, to
Fig. 1, there is schematically illustrated at 10 a process
for forming the materials of the present invention.
An elastic sheet 20 is unwound from a supply roll 22
and travels in the direction indicated by the arrow
associated therewith as the supply roll 22 rotates in the
direction of the arrows associated therewith. The elastic
sheet 20 passes through a nip 24 of a S-roll arrangement 26
formed by the stack rollers 28 and 30.
The elastic sheet 20 may be formed by known nonwoven
extrusion processes, such as, for example, known
meltblowing processes or known spunbonding processes, and
passed directly through the nip 24 without first being
stored on a supply roll.
A layer of generally individualized fibrous materials
is unwound from a supply roll 42 and travels in the
direction indicated by the arrow associated therewith as
the supply roll 42 rotates in the direction of the arrows
35 associated therewith. The layer of fibrous materials 40
X
11
passes idler roller 44 as it is overlaid onto the elastic
sheet 20. Generally speaking, the fibrous materials 40 may
be formed by extrusion processes such as, for example,
meltblowing processes or other processes such as, for
example, carding processes and overlaid onto the elastic
sheet 20 without first being stored on a supply roll.
Desirably, the fibrous materials 40 may be in the form of
an individualized fiber web or batt such as an un-bonded
web of fibers (e.g., a carded web of fibers or a layer of
loose fibers deposited directly upon a carrier sheet) which
is transported to elastic sheet 20.
The elastic sheet 20 passes through the nip 24 of the
S-roll arrangement 26 in a reverse-S path as indicated by
the rotation direction arrows associated with the stack
rollers 28 and 30. From the first S-roll arrangement 26,
the elastic sheet 20 is overlaid with the layer of fibrous
materials 40 as both the elastic sheet 20 and the layer of
fibrous materials 40 pass through a nip 50 of a first drive
roller.arrangement 52. Because the peripheral linear speed
of the rollers of the S-roll arrangement 26 is controlled
to be less than the peripheral linear speed of the rollers
of the first drive roller arrangement 52, the elastic sheet
20 is tensioned between the S-roll arrangement 26 and the
nip of the drive roller arrangement 52. By adjusting the
difference in the speeds of the rollers, the elastic sheet
20 is tensioned so that it stretches a desired amount. The
Layer of fibrous materials 40 may also pass through the nip
24 of the S-roll arrangement 26 and be stretched along With
the elastic sheet between the S-roll arrangement 26 and the
first drive roller arrangement 52.
The elastic sheet 20 is maintained in a uniformly
stretched condition as the fibrous materials 40 are
attached to the stretched elastic sheet 20 during their
passage through the fiber attachment apparatus 60 because
the peripheral linear speed of the rollers of a second
drive roller arrangement 70 is controlled to be
approximately the same as the peripheral linear speed of
CA 02077247 2001-11-05
12
the rollers of the first- drive roller arrangement 52.
After passing drive rollers 70, the tension which elongates
the elastic sheet 20 with the attached fibrous materials 40
is released so that the attached fibrous materials 40 are
positioned more closely together by the recovery of the
elastic sheet 20 to form a resulting composite elastic
material 75 that is stored on a wind-up roll 80.
Other methods of stretching the elastic sheet 20 while
the fibrous materials 40 are attached to the elastic sheet
20 may be used such as, for example, tenter frames or other
cross-machine direction stretcher arrangements that expand
the elastic sheet in one or several other directions such
as, for example, in both the machine and the cross-machine
direction.
Generally, any suitable elastomeric sheet forming
resins or blends containing the same may be utilized for
the elastic nonwoven web of fibers. For example, the
elastic sheet 20 may be made from block copolymers having
the general formula A-B-A' where A and A' are each a
thermoplastic polymer endblock which contains a styrenic
moiety such as a poly (vinyl arene) and where B is an
elastomeric polymer midblock such as a conjugated diene or
a lower alkene polymer.
The elastic sheet 20 may be formed from, for example,
(polystyrene/ poly(ethylene-butylene)/polystyrene) block
copolymers available from the Shell Chemical Company under
the trademark KRATON G. One such block copolymer may be,
for example, Kraton'" G-1657.
Other exemplary elastomeric materials which may be used
to form the elastic sheet 20 include polyurethane
elastomeric materials such as, for example, those available
under the trademark ESTANE~ from B. F. Goodrich & Co.,
polyamide elastomeric materials such as, for example, those
available under the trademark PEBAX~ from the Rilsan
Company, and polyester elastomeric materials such as, for
example, those available under the trademark
HYTREL~ from E. I. DuPont De Nemours & Company. Formation
CA 02077247 2001-11-05
..
13
of elastic sheets from polyester elastic materials is
disclosed in, for example, U.S. Patent No. 4,741,949 to
Morman et al. The elastic sheet may also be formed from elastic copolymers of
ethylene
and at least one vinyl monomer such as, for example, vinyl ester monomers,
unsaturated
aliphatic monocarboxylic acids and alkyl esters of such unsaturated
monocarboxylic
acids. These elastic copolymers and methods of forming elastic sheets from
such
materials are disclosed in, for example, U.S. Patent No. 4,803,117.
to
A polyolefin may also be blended with the elastomeric
polymer to improve the processability of the composition
when using nonwoven extrusion processes. The polyolefin
must be one which, when so blended and subjected to an
appropriate combination of elevated pressure and elevated
temperature conditions, is extrudable, in blended form,
with the elastomeric polymer. Useful blending polyolefin
materials include, for example, polyethylene, polypropylene
and polybutylene, including polyethylene copolymers,
polypropylene copolymers and polybutylene copolymers. A
particularly useful polyethylene may be obtained from the
U.S.I. Chemical Company under the trademark
Petrothane NA 601 (also referred to herein as PE NA 601 or
polyethylene NA 601) . Two or more of the polyolefins may
be utilized. Extrudable blends of elastomeric polymers and
polyolefins are disclosed in, for example, U.S. Patent No.
4,663,220 to Wisneski et al.
The elastic sheet 20 may also be a pressure sensitive
elastomer adhesive sheet. For example, the elastic
material itself may be tacky or, alternatively, a
compatible tackifying resin may be added to the extrudable
elastomeric compositions described above to provide an
-elastic sheet 20 that can act as a pressure sensitive
adhesive, e.g., to help bond the elastic sheet 20 with the
fibrous materials 40. In regard to the tackifying resins
~ CA 02077247 1999-OS-07
14
and tackified extrudable elastomeric compositions, note the
resins and compositions as described in U.S. Patent No.
4,789,699 to Kieffer et al.
Any tackifier resin can be used which is compatible
with the elastomeric polymer and can withstand the high
processing (e. g., extrusion) temperatures. If blending
materials such as, for example, polyolefins or extending
oils are used, the tackifier resin should also be
compatible with those blending materials. Generally,
hydrogenated hydrocarbon -resins are preferred tackifying
resins, because of their better temperature stability.
REGALREZ" and ARKON" P series tackifiers are examples of
hydrogenated hydrocarbon resins. ZONATAK"501 lite is an
example of a terpene hydrocarbon. REGALREZ" hydrocarbon
resins are available from Hercules Incorporated. ARKON" P
series resins are available from Arakawa Chemical (U.S.A.)
Incorporated. Of course, the present invention is not
limited to use of such three tackifying resins, and other
tackifying resins which are compatible with the other
components of the composition and can withstand the high
processing temperatures, can also be used.
Thus, a pressure sensitive elastomer adhesive sheet
which is useful for the composite elastic materials of the
present invention may be formed from a blend containing,
for example, about 40 to about 80 percent, by weight, A-B-
A~ block copolymer; about 5 to about 40 percent, by weight,
polyolefin; and about 5 to about 30 percent, by weight,
tackifying resin.
Tackiness may also be imparted to the elastic sheet 20
by using a solvent that causes the elastic to become tacky
without substantially weakening the elastic. The solvent
is then substantially evaporated from the elastic sheet
after the elastic sheet 20 and the fibrous materials 40
have been joined.
The elastic sheet 20 may also be a multilayer material
in that it may include two or more individual coherent webs
CA 02077247 1999-OS-07
before being combined with the fibrous materials 40.
Additionally, the elastic sheet 20 may be a multilayer
material in which one or more of the layers contain a
mixture of elastic and nonelastic fibers or particulates.
5 An example of the latter type of elastic sheet, reference
is made to U.S. Patent No. 4,209,563, in which elastomeric and non-elastomeric
fibers
are commingled to form a single coherent web of randomly dispersed fibers.
Another
example of such a composite web would be one made by a technique such as
disclosed
10 in previously referenced U.S. Patent No. 4,741,949. That patent discloses
nonwoven
materials which include a mixture ofmeltblown thermoplastic fibers and other
materials.
The fibers and other materials (e.g., wood pulp, staple fibers or particulates
such as, for
example, hydrocolloid (hydrogel) particulates commonly referred to as
superabsorbents)
are combined in the gas stream in which the meltblown fibers are carried so
that an
intimate entangled commingling of the meltblown fibers and the other materials
occurs
prior to collection of the fibers upon a collecting device to form a coherent
web of
randomly dispersed fibers.
The fibrous materials 40 may be fibers or fiber
bundles. If the fibrous materials are fibers, they may be
in the form of a nonwoven web of individualized fibers such
as, for example, a nonwoven web in which the fibers are
substantially un-bonded so that they are loose and may be
easily adhered to and/or inserted into the elastic sheet
2 0 . Such an un-bonded web or batt of fibers may be , f or
example, a carded batt of staple fibers or a web of loose
meltblown fibers.
If the nonwoven web contains meltblown fibers, the
meltblown fibers may also include microfibers. The
meltblown fibers may be made of fiber forming polymers such
as, for example, polyolefins. Exemplary polyolefins for
use in the nonwoven web include one or more of
polypropylene, polyethylene, polybutylene, ethylene
CA 02077247 2001-11-05
16
copolymers, propylene copolymers, and butylene copolymers.
Useful polypropylenes include, for example, polypropylene
available from the Himont Corporation under the trademark
PC-973, polypropylene available from the Exxon Chemical
Company under the trademark ExxonT"' 3445, and polypropylene
available from the Shell Chemical Company under the
trademark DXSA09.
The fibrous materials 40 may also be a mixture of two
or more different fibers or a mixture of fibers and
particulates. Such mixtures may be formed by adding fibers
and/or particulates (e':g., wood pulp, staple fibers and
particulates such as, for example; hydrocolloid (hydrogel)
particulates commonly referred to as superabsorbent
materials) to the gas stream which carries the meltblown
fibers. As a result, the meltblown fibers and the other
materials may be intimately entangled and mixed prior to
collection of the meltblown fibers upon a collecting device
to form a coherent web of randomly dispersed meltblown
fibers and other materials such as disclosed in previously
referenced U.S. Patent U.S. Patent No. 4,741,949.
The fibrous materials 40 may also be in the form of a
loose batt or web of individualized staple fibers, wood
pulp fibers or mixtures of the above. Typical mixtures of
wood pulp fibers and staple fibers contain from about 20 to
about 90 percent by weight staple fibers and from about 10
to about 80 percent by weight~wood pulp fibers.
The staple fibers may have a denier in the range of
about 0.5 to about 100 and an average length in the range
of about 0.5 inch to about 6 inches. The fibrous materials
40 may be natural fibers such as plant, animal or mineral
fibers, such as, for example, cotton, wool or asbestos.
The staple fibers may be either crimped or uncrimped
fibers. Pulp fibers including long natural fiber pulps
such as, for example, hardwood pulps may also be used. The
fibrous materials 40~may also be man-made fibers such as
reconstituted cellulose fibers or synthetic polymer fibers.
For example, the fibers may be one or more of rayon,
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17
polyester, polyamides, and acrylics. Polyolefins may also
be used, including, for example, one or more of
polyethylene, polypropylene, polybutylene, polyethylene
copolymers, polypropylene copolymers and polybutylene
copolymers. Bi-component or mufti-component fibers may also
be used including, for example, side-by-side and sheath
core bicomponent fibers. Microdenier fibers may be used
in situations such as, for example, when flocking processes
are utilized. Fibers used in flocking processes may have
an average length as low as 0.075 inch.
As noted previously, the individualized fibrous
materials 40 may be fiber bundles such as, for example,
yarns, threads, twines or multifilament materials. Fiber
bundles may be used with equipment such as, for example,
tufting machines or stitchbonding machines which
individually insert the fiber bundles into the stretched
elastic sheet 20 by tufting processes or stitchbonding
processes rather than by being deposited dixectly upon the
stretched elastic sheet 20 and then inserted by a needling
operation or adhered by a flocking operation.
The type of individualized fibrous materials 40 which
are attached to the elastic sheet 20 as well as the density
at which they are attached will affect the basis weight of
the resulting composite elastic material 75. The composite
elastic material 75 may have a basis weight ranging from
about 10 gsm to 150 gsm or more.
The density at which the fibrous materials 40 are
attached to the elastic sheet will vary depending on, for
example, the type of fibrous materials used, the elongation
at which the elastic sheet is maintained while the fibrous
materials are being attached to the elastic sheet, and the
amount that the elastic sheet recovers upon release of the
stretching force.
If the fibrous materials 40 are individualized fibers,
they may be attached to the elastic sheet 20 by mechanical
needling. Mechanical needling may be carried out on
needlepunching machines such as, for example, down-punch
CA 02077247 2001-11-05
I8
board machine Model No.- DS-2E, up-punch board machine Model
No. SM-4E and double-punch needling machine DF-4E,
available from Asselin America, Inc., Charlotte, North
Carolina. Needle boards having a needle density from about
30 needles per inch to greater than 240 needles per inch
may be used for most applications.
The fibers of the fibrous materials 40 may also be
attached to the elastic sheet 20 while the elastic sheet 20
is in the stretched condition utilizing flocking processes
such as, for example, electrostatic flocking or vibration
flocking. In flocking..processes, an adhesive is applied to
a substrate and fibers are implanted into the adhesive
using electrostatic forces, compressed air or by applying
fibers onto the adhesive and then vibrating the substrate
with a beater bar to drive the fibers into the adhesive.
An adhesive which remains elastic after it sets should be
used if a flexible and elastic flocked composite material
is desired. Suitable adhesives include, for example,
latex-based flock adhesives such as, for example, adhesives
available from the B.F. Goodrich Company under the
trademark Geon° and Hycar°; adhesives available from the
Rohm & Haas Company under the trademark Rhoplex°;
and adhesives available from Permuthane, Incorporated under
the trademark Permuthane°. The adhesives may be
applied to the elastic sheet 20 by knife-coating, screen-
printing or spraying and will set to form a flexible,
elastic, and tack free coating which will adhere to many
substrates and fibers.
If the fibrous materials 40 are fiber bundles, the
fiber bundles may be attached to the elastic sheet 20,
utilizing conventional tufting equipment such as tufting
machines available from the Card-Monroe Corporation, Hixon,
Tennessee, and the Cobble Tufting Machine Company, Dalton,
Georgia. The needle gauge of the tufting machines may vary
. from about 5/32 inch to about 1/20 inch with the pile
height varying from about 5 mm to about 3 mm. The tuft
density may range from about 39 tufts per 10 square
~~'~p~~a ~~'l~~.i
19
centimeters to about 106 tufts per 10 square centimeters as
measured while the elastic sheet is maintained in an
elongated condition.
The elastic sheet 20 should be held under substantially
uni:eorm tension while being mechanically needled or tufted
to avoid damage to the punch needles or tuft needles. If
the elastic sheet 20 is not held securely so that the
tension is uniform while it is mechanically needled or
tufted, the punch needles or tuft needles may bend and
break if they are deflected by non-uniform movements of the
elastic sheet 20. The elastic sheet 20 may be held using
methods such as, for example, a set of nip rolls rotating
at the same speed positioned before and after the
mechanical needling apparatus. It is also advantageous to
hold the elongated elastic sheet under uniform tension
during other fibrous material attachment processes such as,
. for example, flocking processes to increase the uniformity
of the resulting increased pile density composite elastic
material.
Stretching the elastic sheet 20 while fibrous materials
40 are being attached onto the elastic sheet will provide
desirable characteristics to the resulting composite
material as well as advantages to the fiber attachment
process. These characteristics include, fax example,
increased pile density, and/or enhanced fleeciness or
lanate characteristics, improved retention of the fibrous
materials in the elastic sheet, and improved elongation
over equivalent elastic composite materials in which the
fibers are attached while the elastic is unstretched.
Additionally, the method of the present invention is
especially well suited for mechanical needling because high
densities of fiber insertion can be accomplished without
multiple passes through the needling apparatus. Such
multiple passes typically cause matting of the fibers and
may destroy the lanate or fleece-like characteristics of
the composite material. Materials having lanate or fleece-
lice characteristics are desirable not only for their
~'e"~'J,"Si""lr.:!!~
<.: 1
insulation properties but also for soft hand and fabric
texture.
Materials of the present invention having lanate
characteristics typically have low densities. For example,
5 the materials may have a density ranging from about 0.2 to
about 0.04 grams per cubic centimeter. The lanate
composite elastic materials also have desirable insulation
properties. Lanate composite elastic materials of the
present invention may have a normalized dry heat transfer
10 rate of at.least about 15 Clo/gram/cubic centimeter. For
example, the lanate composite elastic materials may have a
normalized dry heat transfer rate from about 16 to about 30
Clo/gram/cubic centimeter. More particularly, the lanate
composite elastic materials may have a normalized dry heat
15 transfer rate from about 18 to about 21 Clo/gram/cubic
centimeter.
Lanate composite elastic materials of the present
invention .may have a wet heat transfer rate of less than
about 3.1 Watts/MZ~°C. Far example, the lanate composite
20 elastic materials may have a wet heat transfer rate from
about 3.0 to about 2.7 Watts/M2~°C. More particularly, the
lanate composite elastic materials may have a wet heat
transfer rate from about 2.9 to about 2.8 Watts/Mz~'C.
The lanate composite elastic materials of the present
invention may have desirable moisture vapor transmission
rates; that is, moisture vapor easily penetrates the
materials to improve the comfort of a person wearing a
garment which contains the composite material. For
example, the lanate composite material may have a
permeability index of at least about 0.5. For example, the
Ianate composite elastic materials may have a permeability
index greater than about 0.55. More particularly, the
lanate composite elastic materials may have a permeability
index greater than about 0.57.
One important feature of the materials of the present
invention is that they may be designed to combine softness,
drapeability, conformability, insulation and permeability
W" x~~~~~~
21
with highly desirable elasticity. Insulation having
elastic properties is expected to be very useful in
applications such as apparel and blankets. Generally
speaking, the stretch and recovery properties of the
present materials is believed to provide insulation having
longer life and enhanced performance when subjected to
stretching and compression and similar forces commonly
encountered in apparel and bedding applications.
Although the inventors should not be held to a
particular theory of operation, the mechanical needling of
individualized nonelastic fibrous materials into an elastic
sheet while the elastic sheet is maintained in a stretched
condition improves the elasticity of the resulting
composite material because the process appears to minimize
fiber-to-fiber entanglement between the nonelastic fibrous
materials which restricts the ability of the elastic sheet
to stretch.
The effective needling density or needling rate of a
fiber ,inserting apparatus such as, for example, a
mechanical needling machine, tufting machine or a
stitchbonding machine may be increased without increasing
the number of needlestrokes per minute or the density of
the needles. This may be accomplished by elongating an
elastic sheet and then passing the elongated elastic sheet
through the fiber inserting apparatus. For example, a
needle punch machine having a needle-stroke rate of 2000
strokes/minute and operating at a speed of 20 meters/minute
will punch the elastic sheet approximately 100 times/meter
With each needle. If the elastic sheet is elongated to a
length which is 200% of its relaxed length (i.e., 100
percent elongation) and the elongated elastic sheet is
processed at the same needlestroke rate of 2000
strokes/minute and the same speed of 20 meters/minute then,
upon relaxation of the elastic sheet, the needlepunch
machine will have punched the elastic sheet the equivalent
of 200 times/meter with each needle.
era ~ r~..5,~~..~ 4.~ ,'! ,.~
dra!_, ?' ;f'.,,!zi
22
When used with mechanical needling equipment, the
method of the present invention may be used to produce
composite elastic materials having a much more, lanate or~
fleece-like appearance than conventional mechanically
needled composite materials (i.e., where the substrate
remains unstretched during needling), especially when the
materials are subjected to multiple passes of mechanical
needling. Furthermore, conventional hydraulic entangling
processes, especially multiple-pass processes may produce
composites of fibrous materials and elastic substrates
having good fiber retention but which are so intertwined
that the entangled fibrous materials are unable to protrude
from the substrate to form a lanate or fleece-like
material. Such hydraulically entangled materials may also
have high densities and relatively low drape or
conformability. Utilizing the method of the present
invention, composite elastic materials may be made in which
the attached .fibrous materials protrude at, least about 1
millimeter from the surface of the elastic sheet to form a
dense pile or lanate, fleece-like surface with desirable
fiber retention. Composite elastic materials may be
produced having fibrous materials which protrude from about
1 millimeter to more than 3 millimeters from the surface of
the elastic sheet.
For example, an elastic sheet may be elongated
approximately 100% (i.e. approximately 200% of its relaxed
length) and fibrous materials may be mechanically needled
into the elongated elastic sheet, then if the elastic sheet
is allowed to recover to about its original unstretched
dimension (e. g., within about 20% to 25% of its original
unstretched dimension because of the added bulk of the
inserted fibrous materials), the mechanical needling sites
spaced 1" apart in the elongated elastic sheet will
contract to a spacing of 0.6" to 0.625" apart in the
relaxed fabric. This decrease in the separation between
mechanical needling sites upon recovery of the elastic
sheet will cause fibers that are attached to the elastic
CA 02077247 2001-11-05
.7
23
sheet at multiple punch sites to extend further out from
the elastic sheet because the length of the fibrous
material between the punch sites, also commonly known as
the runner length, remains constant. That is, a fiber
extending above the elastic substrate, for example, about
0.25" and anchored at, for example, two punch sites about
1" apart when the elastic is stretched will typically, upon
relaxation of the elastic sheet so the punch sites are
spaced about 0.6" apart, extend about another 0.2" from the
elastic substrate which is about the same distance as the
recovery of the elastic material.
Composite elastic materials according to the present
invention may be made utilizing low basis weight elastic
nonwoven webs because the method of the present invention
allows individualized fibrous materials to be incorporated
into low basis weight elastic nonwoven webs without
substantially deteriorating the elastic nonwoven webs and
because the retraction of the elastic nonwoven webs helps
to hold or lock the pile fibers into the low basis weight
elastic sheet.
EXAMPLES
An unstretched elastic sheet of meltblown ARNITEL~
polyetherester fibers made in accordance with the teachings
of U. S. patent No. 4,707,398 and having a basis weight of
1 ounce per square yard (osy) was joined to a batt of 3
denier polyethylene terephthalate (PET) fibers having a
basis weight of approximately 1.5 osy. ARNITEL~ is the
trademark for a melt processable polyetherester
that is from available A. Schulman, Inc. of Akron, Ohio or
DSM Engineering Plastics, North America, Inc., of Reading,
Pennsylvania. The elastic sheet and the batt of PET fibers
were joined by mechanical needling at a rate of about 500
strokes/minute traveling at a speed of 5.4 meters/minute
_(92.6 strokes/meter) on an Asselin Model SD 351M04
Needlepunch machine utilizing a down punch needle board
with 6 rows of 36 RBA needles at a density of about 139
~r~''1~'".i"''9~n/'~ 1"'j
~a .,~' ;~ ;',a x.'
<..
24
needles/inch. The needlepunch machine was set so that the
needle penetration was 18.4 mm. The physical
characteristics and Grab Tensile Test results for this
composite material were determined utilizing the equipment
and procedures detailed below and are reported in Table 1
under the heading "Unstretched".
A section of the same elastic sheet of meltblown
polyetherester fibers having a basis weight of 1 osy was
elongated approximately 263 percent in the machine
direction and was joined while in the elongated condition
to an un-bonded 1.5 osy batt of 3 denier polyethylene
terephthalate (PET) fibers which was also elongated
approximately 263 percent in the machine direction. The
elastic sheet and the batt of fibers were joined utilizing
the Asselin needle punching machine with the same needle
board and at the same conditions as the unstretched
material except that the mechanical needling of the
elongated materials was carried out at a rate of about 850
strokes/minute and at a speed of 9.2 meters/minute (92.4
' 20 strokes/meter). The physical characteristics and Grab
Tensile Test results for this composite material were
determined utilizing the equipment and procedures detailed
below and are reported in Table 1 under the heading
"Stretched".
The lanate composite elastic material. produced using
the method of the present invention had a basis weight of
4.9 osy. The composite elastic material produced by
mechanically needling the unstretched elastic sheet had a
basis weight of 5.5 osy. The inventors attribute the lower
basis weight of the increased pile density material to the
incomplete recovery of the elastic base sheet because of
the inserted fibrous materials and the void volume between
the fibrous materials held within the elastic base sheet.
Grab Tensile Tests were conducted essentially in
accordance with Method 5100 of Federal Test Method Standard
No. 191A, utilizing samples of the entangled material
having a width of about 4 inches and a length of about 6
r~~N ~'~~ '~~
inches. The samples were held at opposite ends by a one
(1) square inch gripping surface. The samples were tested
using an Intellect II tensile testing apparatus available
from Thwing Albert having a (3) inch jaw span and a
5 crosshead speed of about (12) inches per minute. Values
for peak load, peak energy absorbed, peak percentage
elongation, total energy absorbed and total percentage
elongation were determined.
Drape stiffness measurements were performed using a
10 stiffness tester available from Testing Machines,
Amityville, Long Island, New York 11701. Test results were
obtained in accordance with ASTM standard test D1388-64
using the method described under Option A (Cantilever
Test).
15 The air permeability of each sample was determined in
accordance with Method 5450 of Federal Test Method Standard
No. 191A.
The following Table 1 includes the basis weight, bulk,
density, tensile test data, drape and air permeability
20 results for the lanate composite elastic material of the
present invention and the previously described unstretched
mechanically needled composite elastic material. Tensile
test data indicates significant differences in load,
elongation and energy at greater than the 90% confidence
25 level. The tensile load and energy values for the
materials are also expressed as the tensile load and energy
per unit weight of the material. This was accomplished by
dividing the test results for each material by the
material s basis weight.
~~~~,~~~°."~~~rY l
~a r.. ~
26
TABLE 1
Type of Material: Unstretched Stretched
Mean s Mean s_
E3asis weight 5.53 osy 0.27 4.90 osy 0.29
Bulk 0.034 in. 0.005 0.033 in. 0.006
Density 0.13 oz/in3 0.11 oz/in3
Machine Direction Grab TensileTest Results
TensileLoad' 9.3 1.1 10.2 2.5
TensileLoad2 1.7 2.4
PercentElong. 148.8 10.9 177.1 37.2
Energy3 19.0 2.9 26.8 9.7
Energy4
3.4 5.5
Cross-Machine Results
Direction
Grab
Tensile
Test
TensileLoad' 9.1 3.4 14.0 6.4.
TensileLoad2 ~ 1.6 2.9
Percen~Elong. 56.8 7.9 82.3 15.4
Energy 5.9 2.6 11.5 7.4
Energy4 1.1 2.1
Draaes
Machine 2.71 0.258 2.66 0.774
Direction
Cross-Machine 0.940 3.70 0.570
Direction
3.98
Air Permeabilityb 111.5 5.59 112.8 12.1
1 = 1 bsf
2 = lbsf/ounce
3 = (lbsf * inch)/inch2
4 = (lbsg * inch)/(inch2 * ounce)
= inches
6 = cubic feet per minute
~. '~~;. ~'r~~ ~.°, lx,~
27
An elastic sheet of meltblown ARNITEL~ polyetherester
fibers as described above (e.g., basis weight, of about 1
osy) was stretched approximately 15 percent and maintained
in. its stretched condition while it was joined to two batts
of crimped polyester staple fibers (i.e., one batt on each
side of the elastic sheet). The polyester staple fiber
batts contained a mixture of about 50 percent, by weight,
6 denier crimped fibers and about 50 percent, by weight, 15
denier crimped fibers. The staple fibers had an average
length of about 3 inches. Each batt of polyester fibers
had a basis weight of about 3.5 osy.
The layers were joined utilizing two needling machines
arranged in series. First, the fiber batts were tacked to
the elastic layer utilizing a conventional tack needling
machine. The tack needled fiber batts then were passed
through a conventional~top and bottom needling machine
(available from Oskar Dilo of Eberbach,.Germany) which
needled both sides of the composite. The top and bottom
needling machine Was equipped with 25 gauge Groz-Beket
needles mounted on a low-density needle board having a
needle density of about 80 needles per inch. The needling
was carried out under standard conditions for the
particular fiber batt and low-density needle board. Upon
recovery of the elastic sheet, the basis weight of the
needled composite was about 8 osy.
Physical properties of the needled composite material
were measured. The elongation of the composite was
measured by the Grab Tensile Test method described above.
Bulk or thickness of the sample was measured at an applied
pressure of about 25 gramsfor~e Per square centimeter.
The needled composite material was sandwiched between
two pieces of a conventional nylon textile, each piece
having a basis weight of about 6.5 osy. This was done to
simulate apparel construction in which an insulating layer
is located between an outer and inner fabric shell.
CA 02077247 1999-OS-07
28
Thermal resistance and permeability of this apparel
construction were determined in order to evaluate the
effectiveness of the needlepunched composite as an
insulation material. The thermal analyzing system was
composed of two parts: (1) an environmental control
chamber which was maintained at a standard condition: 21
degrees Centigrade, 65% Relative Humidity; and (2) a
component to stimulate the skin/body.
The environmental control chamber was a Tabai ESPEC'sTM Platinous Lucifer
Model PL-2G, programmable temperature and humidity chamber. This chamber
housed
a sub-chamber made from LuciteTM plastic that provided precise control of air
velocity.
A skin simulating guarded hot plate, or sweating hot plate, was positioned
inside the sub
chamber. Air currents impinged vertically on the surface of the guarded hot
plate at a rate
of about 20 cm/sec.
Simultaneous heat and moisture transfer was measured
using a sweating hot plate. This~sweating hot plate
featured four simulated sweating glands that supplied water
to the heated surface at the rate of 0.077 ml/min per
gland. The water flow was controlled using an Ismatec
cartridge peristaltic pump while the surface of the hot
plate was covered by a highly wettable and dimensionally
stable polyester/rayon-spunlace nonwoven membrane to allow
water to easily spread over the surface. Two simulated
skin-clothing models were used: (1) a standard dry model,
and (2) a standard wet model. A guarded hot plate was used
as a heat source for the standard dry model. A sweating
hot plate was used as the heat source for the for the
standard wet model. In both models, specimens were placed
directly on the heat source.
The amount of heat and rate of heat flow through a
specimen during testing was measured utilizing a box
containing a thin copper heat capacitor fitted with a
temperature sensing device. These components were placed
between the heat source (i.e., the hot plate) and the
specimen to detect the rate at which heat was pulled from
~o'y'"y."i r;~ /'~ ~~
i~t ~~ ~ 'J J . ~~ x
29
a finite thermal capacity (e.g., simulated skin) through a
fabric.
The Dry Heat Transfer rate was measured and reported in
units of Watts/Mz~°C. Thermal resistance was calculated
from the measured Dry Heat Transfer rate utilizing the
following equation:
Thermal Resistance = (1/Dry Heat Transfer Rate)/0.155
Thermal resistance is reported in units of clo. The clo
is a unit of thermal resistance defined as the amount of
thermal resistance provided by an arbitrarily selected
standard set of clothing. It may be expressed by the
following equation:
1 clo = ((0.18°C)(meter)Z(hour))/(kilocalories)
The highest clo value represents the lowest heat f low
through the material and is predicted to be the better
insulator. Fox the purpose of comparison, values for
thermal resistance was calculated from the reported Wet
Heat Transfer rate.
The Permeability Index (Im) of the sample was calculated
from the measured Dry Heat Transfer rate and Wet Heat
Transfer rate. The permeability index is defined as the
ratio of the thermal and evaporative resistance of the
fabric to the ratio of thermal and evaporative resistance
of air. This ratio (i.e., the permeability index), which
may have a value that is between 0 and 1, serves as a
measure of how readily moisture vapor and heat pass from
the body through a material to help maintain body comfort.
A higher index value (>1) is generally equated with better
comfort. The permeability index may be calculated using
the following formula:
Im = 0.0607 (E/H) (Ts~Ta) / (Ps-Pa)
where,
CA 02077247 1999-OS-07
E = heat transfer rate (W/mz~ °C.T) due to moisture
evaporation, (Wet Heat Transfer - Dry Heat Transfer)
H = heat trans f er rate ( W/MZ ~ ° C . T ) due to heat , ( Dry
Heat Transfer)
Ps(T) - exp (16.6536-4030.183/(T+235))
Pa (T) - (RH/100)Ps (T)
Ts and Ta are the temperature on the skin surface
and the ambient environment, respectively, and RH
is the relative humidity.
10 Ts = 35°C, Ta = 21°C Rh = 65%
Ps and Pa are water vapor pressures (kPa) on skin
surface and in ambient environment, respectively.
Dry Heat Transfer rates and Wet Heat Transfer rates were
also measured for a batt of standard goose down used as
15 thermal insulation in apparel (80%, by weight, goose down,
20%, by weight, goose feathers); a sample of Thinsulate~
thermal insulation material available from Minnesota Mining
and Manufacturing Company (3M) of Saint Paul, Minnesota;
and ThennoloftTM protective insulation of Dacron~ polyester fibers available
from E.
2 ~ I. Du Pont de Nemours & Company. The results of these tests are reported
in Table 2
As can be seen from Table 2 the samples were not uniform
in weight or bulk. Accordingly, the data was normalized to
provide a meaningful comparison. The test results indicate
25 that composite materials of the present invention provide
a level of desirable insulation properties which is
generally similar to such well known insulation materials
as goose down, Thinsulate~, and a batt of Dacron~ polyester
fibers while also providing desirable stretch and recovery
30 properties which are especially desirable for applications
such as, for example, apparel, blankets, sleeping bags and
the like.
e-d ~N'~"'~.w''!
~~, a' a :-a ~~z
31
TABLE 2
_PHYSICAL PROPERTIES
Basis Stretch' &
Bulk' Wei.hc~tZDensitv3 Recoverv4
Goose Down 20.14618.69 0.031 -
Thinsulate~ 7.117 14.18 0.067 -
Needle Punched Demique~9.183 15.69 0.057 221
Dacron~ Polyester 7.983 11.27 0.047 -
1 = millimeters
2 = ounces per squarerd
ya
3 = grams per cubic imeter
cent
4 = percent
DRY HEAT TRANSFER
Clo Clo cm Clo cm3
Goose Down 1.33 0.66 42.90
Needle Punched Demique~1.13 1.23 19.82
Thinsulate~ . 1.08 1.52 16.22
Dacron~ Polyester 1.00 1.25 21.28
WET HEAT TRANSFER
Watts/MZCClo
Dacron~ Polyester 3.10 0.291
Thinsulate~ 3.07 0.294
Needle Punched Demique~ 2.98 0.303
Goose Down 2.73 0.331
PERMEABILITY INDEX
Down 0.639
Needle Punched Oemique~ 0.579
Thinsulate~ 0.563
Dacron~ Polyester 0.510
~~.ar~".,.~~a;~ ~
a' ;~ , -.: ~ v
32
Thus, it is apparent that the present invention provides
a composite elastic material that reduces. problems
associated with previous pile-type and lanate, fleece-like
materials.
At least one layer of the lanate composite elastic
material and/or the increased pile density composite
elastic material may be combined with at least one other
layer of material to form a multilayer material. For
example, a layer of the lanate composite elastic material
may be sandwiched between a layer of lining fabric and a
layer of shell fabric to form a multi-layer material that
may be cut, shaped, formed, sewn or otherwise used directly
in the manufacture of apparel.
While the invention has been described in conjunction
with specific embodiments, the disclosed embodiments are
intended to illustrate and not to limit the invention. It
is understood' that those of skill in the.art should be
capable of making numerous modifications without departing
from the true spirit and scope of the invention.
