Note: Descriptions are shown in the official language in which they were submitted.
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FIREFIGHTER GARMENT WITH COMBINATION
FACECLOTH AND MOISTURE BARRIER
Background Of The Invention
The present invention relates to garments for wear in
hazardous environments and, more particularly, to firefighter
garments.
In order to meet applicable standards, a firefighter
garment must withstand certain levels of abrasion, heat and
moisture. Typically, these requirements have been met by
providing a firefighter garment having an outer shell made of a
heat and flame resistant aramid fiber such as NOMEX (a trademark
of E.I. DuPont de Nemours & Co., Inc.), a moisture barrier
positioned within and adjacent to the outer shell and a thermal
liner, typically made of a batting of aramid fiber quilted to a
woven facecloth of spun yarn fiber and positioned within and
adjacent to the moisture barrier. Originally, the moisture
barrier was made of a fabric coated with a neoprene rubber
compound which made the moisture barrier impermeable to moisture
vapor as well as liquid vapor.
However, moisture barriers are now available which
comprise a layer of a semi-permeable membrane material such as
GORE-TEX (a registered trademark of W.L. Gore & Associates, Inc.)
adhesively attached to a substrate of an aramid fiber. Such
moisture barriers are impermeable to liquid moisture but allow
moisture vapor to pass through.
A disadvantage with such conventional firefighter
garment construction is that, when worn, the rigors of
firefighting activity results in a build up of excessive levels
of moisture vapor from perspiration of the wearer. The flow of
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such moisture vapor through the semi-permeable moisture barrier
membrane is impeded somewhat by the presence of the thermal liner
material between the wearer and the moisture barrier. Collection
of moisture from the wearer in the thermal liner has been found
to reduce the thermal protective qualities of the thermal liner.
Another disadvantage of such conventional firefighter
garments is that the necessity of placing the moisture barrier
outside the thermal liner, between the thermal liner and outer
shell, exposed the moisture barrier to heat penetrating the
garment before the heat reached the thermal liner. Consequently,
such moisture barriers would be prone to damage and degradation
from exposure to heat.
This disadvantage has been overcome by substituting a
low or non-absorbent material, such as an apertured, unicellular
or closed cell foam laminate for the traditional fabric batting
thermal liner. Such closed cell foams, which are heat and flame-
resistant, do not themselves absorb outside source moisture from
hoses or foul weather, as do conventional woven or fibrous
thermal liners, so that they may be placed outside of the
moisture barrier, between the moisture barrier and outer shell.
This orientation protects the moisture barrier from heat damage,
reducing the cost of repairs to the garment, since the moisture
barrier is often the most expensive and delicate component in the
liner system. It is neither practical nor desirable to place
conventional thermal liners outside the moisture barrier since
such thermal liners would absorb moisture and add to the weight
of the garment. Such non-absorbent thermal liners are disclosed
in commonly-owned copending U.S. Patent 5,697,101 issued December 16, 1997.
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A known practice in the industry is the reduction of
stress experienced by the wearer of a firefighter garment
resulting from the effort required to overcome the frictional
engagement of the wearer's clothing with the interior layer of
the garment during wearer movement by providing a "slippery"
facecloth between the wearer and the thermal barrier of the
garment. Such a slippery facecloth also facilitates the donning
and doffing of the garment. The facecloth is made of a filament
yarn woven or knit into woven or knitted fabric preferably
composed of an aramid fiber such as NOMEX. However, such
firefighter garments having a filament facecloth still embody the
traditional orientation of an outer shell covering a moisture
barrier which, in turn covers a thermal liner.
As a result, such firefighter garments include three
distinct layers: an outer shell, a moisture barrier consisting
of a semi-permeable membrane bonded or laminated to a fabric
substrate and a thermal liner positioned within the moisture
barrier and quilted to a facecloth. Accordingly, there is a need
to provide a firefighter garment having the benefits of a non-
moisture absorbent thermal liner with the stress reduction and
increased work efficiency of garments with filament layers.
Summary
The present invention is a firefighter garment which
has minimal weight, provides sufficient moisture and thermal
protection to meet all applicable standards, including the
N.F.P.A. 1971 Standard, and yet provides optimal moisture vapor
transport outwardly from the wearer while reducing the effort
required -- and energy required -- to move while wearing the
garment, including donning and doffing the garment. The
firefighter garment is unique in that it has combined a moisture
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barrier and low-friction facecloth into a single layer.
Consequently, it places the semi-permeable moisture barrier
substrate closer to the wearer's skin and is additionally unique
since the moisture barrier substrate is made of lower friction
yarns of multifilament high heat resistant fiber such as NOMEX.
In both instances, the result is a combination moisture barrier
facecloth.
A firefighter garment embodying the present invention
includes an outer shell, a non-absorbent thermal liner positioned
adjacent to the outer shell, and a combination moisture barrier
and low-friction facecloth. Consequently, such a garment
efficiently combines the benefits of placing the moisture barrier
adjacent to the wearer and provides a low-friction filament
facecloth to reduce wearer stress and facilitate donning and
doffing of the garment.
In a preferred embodiment of the invention, the thermal
liner comprises a layer of apertured, closed cell foam which is
bonded to a layer of facecloth fabric, the combination being
sufficiently flame and heat resistant to meet applicable N.F.P.A.
Standards. Such a thermal liner absorbs substantially less
moisture than conventional thermal liners and therefore can be
positioned outside the moisture barrier and within the outer
shell because it reduces wet weight gain from sources of moisture
outside the garment. The combination moisture barrier facecloth
comprises a woven or knit of spun or filament yarn which is
bonded or laminated to a semi-permeable membrane material such as
polytetrafluoroethylene ("PTFE") film/membrane or polyurethane
("PU") film/membrane.
The combined moisture barrier and facecloth of the
present invention performs two functions. First, it provides a
moisture barrier which prevents liquid moisture from flowing
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inwardly through the garment to the wearer, and yet promotes
moisture vapor transport generated by evaporation of the wearer's
perspiration outwardly from the wearer. Secondly, (when the
filament yarn is used) the layer provides a lower friction
facecloth which reduces wearer stress. Consequently, the low
friction filament component of the combination moisture barrier
facecloth performs a double duty: it provides a substrate which
protects and supports the moisture barrier membrane, and acts as
a low-friction facecloth interface between the wearer and the
garment. When compared to prior art garments, the ensemble of
the present invention increases the exposure time for a wearer to
sustain a second degree burn by reducing body-generated wet
weight gain which occurs in such traditional systems, and reduces
heat stress because the permeable membrane is closer to the
wearer and enhances comfort.
In another preferred embodiment of the invention, the
thermal liner comprises a layer of flame and heat resistant,
closed-cell apertured foam bonded to a substrate comprised of a
low-friction filament yarn. The thermal liner is oriented in the
garment such that the filament substrate faces the outer shell.
This interface between the outer shell and the thermal liner
further reduces the effort required to move while wearing the
garment since it reduces the friction between the outer shell and
the adjacent thermal liner. This embodiment also includes the
combined moisture barrier and facecloth of low friction filament
fabric to reduce friction between the wearer and the garment.
Accordingly, it is an object of the present invention
to provide a combined moisture barrier and/or low-friction
facecloth which meets applicable NFPA standards; a combined
moisture barrier and facecloth which reduces friction between the
wearer and the associated garment, thereby reducing wearer stress
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and fatigue and facilitating donning and doffing of the garment;
a firefighter garment having minimal weight; a firefighter
garment having a moisture barrier which comprises a semi-
permeable membrane bonded to a substrate that functions as a
protective facecloth; a firefighter garment which minimizes
friction between the outer shell and the adjacent thermal liner
layers; and a firefighter garment which is relatively low in cost
and relatively easy to maintain.
Other objects and advantages of the present invention
will be apparent from the following description, the accompanying
drawings and the appended claims.
Brief Description Of The Drawings
Fig. 1 is a perspective view of a firefighter turnout
coat embodying the present invention; and
Fig. 2 is a detail of the firefighter coat of Fig. 1,
showing the layers of the garment.
Detailed Description
As shown in Fig. 1, the preferred embodiment of the
present invention is in the form of a firefighter turnout coat,
generally designated 10, having a body portion 12, sleeves 14, 16
and collar 18. It is within the scope of the present invention
to provide a complementary pant (not shown), having a similar
construction.
The body 12 and sleeves 14, 16 are covered by an outer
shell 20 (see also Fig. 2) of a flame and heat resistant aramid
fiber such as NOMEX or KEVLAR (a trademark of E.I. DuPont de
Nemours & Co., Inc.). The outer shell 20 is of conventional
design, and may include bands 22, 24 of reflective material
stitched to the outer surface of the outer shell.
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A thermal liner 26 is positioned within the outer shell
and comprises a layer of an apertured closed cell foam material
28 adhesively bonded to a substrate 29 of a woven or knit fabric
of spun or filament yarns. The yarn preferably is made of a
flame and heat resistant material such as an aramid fiber.
Preferred aramid fibers are NOMEX and KEVLAR. The substrate 29
preferably is attached to the layer of apertured, closed cell
foam by a suitable adhesive. In the alternative, the composite
foam 28 and substrate 29 are first bonded together by an
adhesive, then the composite perforated to form the apertured
liner 26. The liner 26 is oriented within the garment 10 such
that the substrate 29 faces the outer shell 20.
The layer of foam material 28 preferably is between
3/32 and 1/8 inches thick and made of a flame and heat resistant
unicellular foam, such as ENSOLITE Styles IVl, IV2, IV3, IV4,
IV5, GIC or IVC, all manufactured by Ensolite, a Division of
Uniroyal Technology Corp. of Mishawaka, Indiana. Such closed
cell foams include foams made of polyvinyl and nitrile rubber
combined with other ingredients to give them high heat
resistance. Although all of the components of the garment 10
provide some minimal insulative function, the layer of foam
material 28 performs the primary insulative function of the
garment.
The thermal liner 26 may be bonded adhesively to the
outer shell 20 by conventional means, such as by a pattern or
matrix of adhesive dots (not shown) of a suitable heat-resistant
adhesive, positioned so that a minimum number of apertures 30 of
the layer 26 are not blocked, or by lines or webs of such
adhesive. In such an embodiment, the thermal liner would not
have the substrate 29 of low-friction material. Alternately, the
thermal liner 26 is not attached to the outer shell, but may be
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removable to facilitate separate cleaning of the outer shell and
liner system. The apertured closed cell foam thermal liner 26 is
described in greater detail in U.S. Patent 5,697,101 issued December 16, 1997
The garment 10 also includes a combination moisture
barrier and facecloth layer 32. Layer 32 comprises a facecloth
34 made of a flame and heat resistant filament yarn, such as
NOMEX material. Other acceptable materials for the facecloth
component 34 are a combination of filament and spun yarns, 100%
multifilament yarns or 1000 spun yarns, or a permanently
chemically or mechanically altered fabric substrate having the
desired degree of lubricity. The facecloth component 34
preferably is a plain weave woven fabric, which is relatively
light, but a twill weave or knit fabric may be used since both
provide less contact surface per unit area than plain weaves. A
moisture barrier material 36 is adhesively bonded to the
facecloth layer 32 by a matrix of dots of heat-resistant adhesive
(not shown). The moisture barrier material 36 preferably is a
PTFE film such as GORE-TEX.
In an alternate embodiment, the moisture barrier
component 36 is bonded to the facecloth component 34 by lines or
webs of heat resistant adhesive (not shown). Also, the moisture
barrier component 36 can be coated or cast onto the substrate
facecloth component 34, which provides a mechanical as well as
chemical attachment.
The thermal liner 26 and combination facecloth and
moisture barrier 32 are continuous throughout the garment; that
is, these layers extend throughout the body 12 and sleeve 14, 16
of the garment to provide thermal and moisture protection.
Further, the combination facecloth and moisture barrier material
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presents a high lubricity surface to the wearer. This high
lubricity surface reduces the friction between the clothing of
the wearer and the garment 10. In addition, the filament
substrate 29 of the thermal layer 26 reduces friction between the
outer shell and the thermal layer. This reduction in friction
reduces the garment's resistance to movement by the wearer, and
thus the effort required to perform movements while wearing the
garment 10 is reduced, and which reduces the energy required to
perform specific tasks. This energy reduction, when it occurs
during harsh firefighting conditions, reduces the stress imposed
on a wearer.
Consequently, the resulting garment 10 comprises an
outer shell 20, thermal barrier layer 26 and combination moisture
barrier/facecloth layer 32. The combined moisture
barrier/facecloth layer 32 performs the double duty of protecting
the waterproof breathable film components of the garment from
abrasion by the clothing of the wearer by virtue of the high
lubricity component 34 of the layer 32, and the same component 34
acts as a substrate for the moisture barrier 36. The ability in
the present invention to combine the moisture barrier/facecloth
is made possible by providing a low or nonabsorbent material for
the thermal liner, such as the closed cell apertured foam thermal
liner 26, which can be placed between the moisture barrier 36 and
outer shell 20. Moisture vapor transport from the wearer through
the garment to the ambient environment is enhanced with the
embodiment of the present invention.
In contrast with prior art garments in which the
moisture barrier is between the thermal liner and the outer
shell, the proximity of the moisture barrier 36 (it is only
separated from the wearer by the facecloth component 34)
maximizes moisture vapor transport rate through the moisture
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barrier. The apertures 30 in the thermal liner 26 enable the
moisture vapor which has passed through the moisture barrier 36
to pass through the thermal liner to the outer shell 20, where it
enters the ambient environment.
While the forms of apparatus herein described
constitute preferred embodiments of the invention, it is
understood that the present invention is not limited to these
precise forms of apparatus, and that other forms may be employed
without departing from the scope of the invention.
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