Note: Descriptions are shown in the official language in which they were submitted.
CA 02543728 1998-08-27
LIGHTWEIGHT FIREFIrs'HTER GARMENT
BACKGROUND
The present invention relates to hazardous duty garments and, more
particui_arly, to lightweight firefighter garments which protect a wearer from
extreme ambient
conditions.
Protective garments are designed to shield a wearer from a variety of
environmental hazards, and firefighter garments are representative of such
garments. A
conventional firefighting ensemble comprises a tuxnout coat and pant, each of
which includes
an outer shell, a moisture burner located within the outer shell, a thermal
Liner located within
the moisture barrier and an innermost face cloth layer. The outer shell
typically is
constructed of an abrasion-, flame- and heat-resistant material such as a
woven aramid
material, typically NOMEX or KEVLAR (both are trademarks of E. I. DuPont de
Nemours &
Co., Inc.) or a polybenzamidazole such a PBI (a trademark of Celanese Corp.)
fiber material.
The moisture barrier typically includes a semipermeable membrane layer which
is moisture
vapor permeable but impermeable to liquid moisture, such as CROSSTECH (a
trademark of
W.L. Gore & Associates, Inc.). The membrane layer is bonded to a substrate of
flame- and
heat-resistant material, such as an aramid or PBI material.
The thermal liner is typically positioned within the moisture barrier in order
to
prevent the thermal liner from soaking up liquid moisture flowing through the
outer shell
from the ambient. The thermal liner typically comprises a relatively thick
layer of aramid
fiber batting or needlepunch, often quilted to a lightweight aramid face
cloth. The batting of
the thermal barrier traps air and possesses sufficient loft to provide the
necessary thermal
resistance, and the face cloth protects the batting of the thermal liner from
abrasion from the
wearer.
The aforementioned components typically are arranged within the garment so
that the moisture barrier layer is positioned between the thermal liner and
the outer shell.
This is necessary to prevent the batting material of the thermal liner from
absorbing an
excessive amount of liquid moisture from the ambient, which increases the
overall weight of
the garment and reduces breathability of the thermal liner, thereby increasing
the stress
CA 02543728 1998-08-27
imposed by the ga.-ment on the v~earer, and reduces its loft and thermal
resistance
characteristics. However, one disadvantage with such an arrangement is that
the laminated
membrane of the moisture barrier is relatively delicate and can be damaged by
heat, abrasion
or puncture. Such damage results in increased exposure of the thermal liner to
liquid
moisture, which increases liquid moisture absorption.
Another disadvantage inherent in such an arrangement is that the, moisture
barrier layer adds to the bulk and weight of the garment and inhibits freedom
of movement of
the wearer, producing a "hobbling effect,'" increasing the stress imposed on
the wearer in
situations requiring high activity, and accelerates the onset of fatigue.
Furthermore, with such
an ensemble some perspiration moisture vapor from the wearer is absorbed by
the thermal
liner. Moreover, the combination of a discrete moisture barrier and thermal
liner limits
breathability, especially if the thermal liner is positioned within the
moisture barrier.
Accordingly, there is a need for a protective garment in which the
susceptibility ~f the thermal Liner to absorption of perspiration moisture
vapor and other
moisture vapor is minimized; a protective garment which is relatively thin and
lightweight,
yet provides adequate thermal protection; a protective garment which is
inherently able to
withstand a temperature of 500° F. for at least five minutes without
igniting, melting or
dripping, making it suitable for use as a firefighting garment; and a
protective garment which
minimizes the restriction of movement and hobbling effect characteristic of
conventional
firefighting garments.
The present invention is a protective garment which is relatively lightweight,
yet possesses relatively high resistance to liquid water absorption but
relatively high moisture
vapor transport characteristics when compared to conventional firefighter
garments. The
garment of the present invention comprises an outer shell, a thermal liner
positioned within
the outer shell, and a face cloth layer positioned within the thermal liner --
a discrete moisture
barrier layer is not present or required. At least the outer shell and the
face cloth layer are
treated with a durable, water repetlant finish to reduce penetration of
moisture through either
of these layers to the thermal liner. Preferably, the thermal liner is also
treated with a durable,
-2-
CA 02543728 1998-08-27
water repellent finish to minimize liquid moisture absorption. Such durable,
water repellent
finishes are provided by treating the components with a commercially available
perfluorohydrocarbon finish such as TEFLON (a trademark of E. I. DuPont de
Nemours &
Co., Inc.). and/or SCOTCHGUARD (a trademark of Minnesota Mining &
Manufacturing
Co.).
In a first embodiment of the present invention, a firefighting garment
consists
essentially of an outer shell of abrasion-, flame- and heat-resistant material
selected from a
group consisting of an aramid material, a blend of aramid materials, PBI
material and a blend
of aramid and PBI materials; a thermal liner positioned within the outer shell
and including a
batting, needlepunch or nonwoven aramid material, or a blend of such aramid
materials,
stitched to a first face cloth layer of aramid material; and a second face
cloth layer of aramid
material, positioned within the thermal liner; where the material of the outer
shell, the thermal
liner, and the second face cloth layer are all treated with a durable, water
repellent finish.
Such a firefighting garment does not require a discrete moisture barrier
layer,
yet possesses the necessary thermal protection ratings for use as a
firefighting garment. Thus,
the firefighting garment is relatively thin and lightweight, thereby
minimizing the bulk and
reducing the hobbling effect of such a garment. Furthermore, the elimination
of a discrete
moisture barrier reduces the material costs of the garment: The design of the
thermal liner
substantially reduces the amount of liquid moisture it absorbs, thereby
maintaining the
insulative properties of the thermal liner and maintaining desirable
lightweight properties for
longer periods. Another advantage of such a design is that the transport of
moisture vapor
through the garment is enhanced.
In an alternate embodiment of the present invention, a discrete moisture
barrier
layer is provided, but is positioned between the treated thermal barrier and
the inner face
cloth. By providing such a moisture barrier, the penetration of blood-borne
pathogens from
the environment to the wearer is minimized. Furthermore, the positioning of
the treated
thermal liner between the outer shell and the moisture barner protects the
moisture barrier
from damage from excessive thermal heat and from abrasion caused by the outer
shell.
In a second alternate embodiment, a firefighter garment includes an outer
shell, a moisture barrier positioned inside and adjacent to the outer shell, a
thermal liner
positioned inside of the moisture burner and an inner face cloth. The thermal
liner is treated
-3-
CA 02543728 1998-08-27
to have a moisture repellant finish as with the other embodiments. The thermal
Iiner of this
embodiment thug will absorb only d 3nln~~~al amount of perspiration rnoistcu-e
frcyrr the
wearer, fiom a breach in the rnoistizre bonier or from openings in the neck
and sleeve, and
generally will be shielded from ambient moisture by the conventional moisture
barrier.
Accordingly, it is an object of the present invention to provide a protective
garment it which the thermal liner absorbs a minimal amount of liquid
moishare; a protective
garment which reduces the amount of moisture absorbed by the thermal liner; a
protective
-garment which does not require a discrete moisture barrier layer, yet
possesses the necessary
thermal protection ratings for use as a firehghting garment; a protective
garment which is
relatively tnin and lightweight, thereny minimizing the bulk and reducing the
hobblinb effect
of such a garment a»d the reducing the material test; of tfze garment; anal a
protective
garment that enhances the transport of rrroisttrre valwr therethrough for
breathability and
greater cc~c~ling.
Qther objects and ~.dvantag~ of the present invention vzll ire apparent from
tha following description, the accompanying 'cravings and the appended claims:
~~'L~~~~SS~'~~~~~~ C'F T~iE~R~WiIyTG~
Fig. ? a a somewhat sch:,matic, perspective view of a f refighter gar_xient
incorporatin ; a preferred embodiment of the present invention;
Fig. 2 is an exploded, perspective view of a section of a detail of the
garment
of Fig. 'I;
Fig. 3 is an exploded, perspective view of a detail of an alternate embodiment
of tI-ze present invention; and
Fag. 4 is an exploded, perspective view of a detail of a second alternate
~r~-ibad:ment of the invention.
r3l;TP,ILED DESCF.TPTIc'~N
A, shown in Fig. I, the present invention is a protective garment in the form
of
a fir~tight~r garment, generally desigrrateo' I~. 1i is to be understood that
the present
CA 02543728 1998-08-27
invention is not limited to firefighter garments, but can be incorporated in
work garments and
other hazardous duty garments, such as brushfire and EMS garments, in both
coat and pant
combinations and njumpsuit" styles, without departing from the scope of the
invention. The
garment 10 is a firefighter turnout coat having a body portion 12, sleeves 14,
16, a neck
opening 18, a collar 20 surrounding the neck opening, and a front closure,
generally
designated 22. Front closure 22 is of conventional design and includes a storm
flap 23. The
closure 22 is secured by snaps, or alternatively, strips of hook and loop
fastener material (not
shown) in combination with mechanical locking means such as hook and "D"
combinations
24 extending between the flap 23 and body portion 12, or a slide fastener (not
shown).
As shown in Figs. 1 and 2, the garment 10 includes an abrasion, heat and
flame resistant outer shell, generally designated 26, which covers
substantially the entire
outer surface garment. The outer shell is compact weave of an aramid material
such as
NOMEX or KEVLAR, a blend of such aramid materials, a PBI material, or a blend
of aramid
and PBI materials. The thermal liner, generally designated 28, extends
substantially
throughout the garment 10 and includes layer 30 of insulative material quilted
to a layer 32 of
aramid face cloth material. The insulation material can be a batting,
needlepunch, or multi-
layer nonwoven aramid material. A second layer 34 of aramid face cloth
material is
positioned within the thermal liner 28 and protects the thermal liner from
abrasion from the
clothing of the wearer. Additionally, it is within the scope of the invention
that the foregoing
materials may be readily substituted with other materials having similar
protective properties,
or alternative protective properties corresponding to other specialized
hazardous use
garments.
The outer shell 26, thermal liner 28 and face cloth layer 34 each are treated
with a durable, water-repellant finish prior to assembling these components to
form the
garment 10. A preferred finish is a perfluorohydrocarbon finish such as TEFLON
Fabric
Protector. Preferably, a loading of at least 2.5% on weight of fabric of
TEFLON is used. A
commercially available method for finishing the above components with TEFLON
Fabric
Protector is provided by E. I. DuPont de Nemours & Co., Inc. of Wilmington,
Delaware,
19898.
It is within the scope of the invention that other suitable water repellant
finishes, coatings or treatments may also be used, such as treating the
components with a
-5-
CA 02543728 1998-08-27
pcrl?uorohydrocarbon finish suoh as SCCTCIIGLT.AStD, or by applying a silicon,
resin, wax
or plastic finish. In the preferre:i ernbodimerst of the ir_vention, each
component cf the
garment ZO p~~ss~sses certain characteristics which makes it particularly
suitable for use in a
hazardous duh~r garment, particularly a h re:igbter garment. The or sernble of
the outer shell
26, thermal liner 28 and face cloth layer 34, each treated with a durable,
water-repellent finish
according to the invention, meets certait~_ reauirements of the I~,1.F.P.A.
~Nationah Fire
Pratec!ion Association) 1971 Standard. Specifically, the esasemble resists
igniting, rnelting or
dripping when exposed to 500°F for at lent five minutes. Furthenrriore,
tae water-repellent
iirislz~ applied tc, øiie components of the enserrible are durable in that
lliey withstarW at least
25 launderings without appreciable diminution in water repellancy.
I-Iowever, a durability of withstanding at least~5 lamderings without
appre~~:abl~ diminution iii water repellancy is ~~ithin the scope of the
invention. -
Consequently, the frefighting garment 10 does not require a discrete moisture
barrier because the vc~ater-repellent iirish of tho outer shell 26 and face
cloth layer 34
substantially prevent liquid moisture from reaching and being absorbed by the
thermal liner
28.. Furthenimre, because the thexrsal Iiner 28 is also preferably irPated
with a water-repellent
finish, it will be much less susceptible to absorbing and retaining liquid
moisture that
p~l~etr'at~s throiPgll the outer shell 26; face cloth layer 34, cc enters
throu;lv a seam or opening.
Ad:iiticnally, by eliminating a discrete moisture ban-ier cr~~?:~ponent, the:
breathability o f the
garment is increased, and the weight and "hobbling" effect of the garrr~ent is
substantially
decreased_
It is also within the scope of the present invention to use a thermal liner
that
includes a layer of apertured, closed-cell foam as described in U.S. Patent
No. 5,697,101
issued December 16, 1997 and U.S. Patent No. 5,924,134 issued July 20, 1999.
Such
thermal liners do not absorb significant amounts of liquid moisture and can be
made thinner
than conventional thermal liners, yet still meet the overall thermal
requirements for
firefighting garments.
'fhc: method of constru~tsl?g the gannc;nt of ahe preseAat invenxior. is as
follows.
A relatively lightweight, low veiunp ; pru~:ecti~'e g,~rment is ~onstruct:~d
by W acing an voter
shell of abrasion, flame ?.rd heat resistant :nateral with a 4urable, u'ater-
repellent tfnis?;
treatiaig a the,~al liner with a durai~ie, »cater rPp~lt~nt finish; treating a
face cloil~ :aver of
_6_
CA 02543728 1998-08-27
material with a durable, water-repellent finish; and assembling the garment by
positioning the
thermal liner within the outer shell and the face cloth layer within the
thermal liner. The
means for cutting and attaching the various layers together to form the
garment will be
apparent to those skilled in the art.
As shown in Fig. 3, an alternate embodiment 10' of a firefighter garment of
the
present invention includes a thermal liner 28 adjacent to the outer. shell 26
as with the
embodiment of Figs. 1 and 2, but includes a discrete moisture barrier layer 36
between the
thermal liner 28 and the face cloth layer 34. The moisture barrier 36 includes
a
semipermeable membrane layer 38, which is moisture vapor permeable but
impermeable to
liquid moisture, such as CROSSTECH, bonded to a substrate 40 of flame- and
heat-resistant
material, such as an aramid or PBl material. By providing such a moisture
barrier 36, the
penetration of blood-borne pathogens from the environment to the wearer is
minimized.
Furthermore, the positioning of the thermal liner 28 between the outer shell
26 and the
moisture barner 36 protects the moisture barrier from damage from excessive
thermal heat
and from abrasion caused by the outer shell. With the embodiment of Fig. 3,
the addition of a
discrete moisiure barner 36 (as opposed to the water-repellent thermal liner
28 acting also as
a moisture barrier for the ensemble) to the ensemble of the outer shell 26,
thermal liner and
face cloth layer 34, the entire ensemble 10' meets the N.F.P.A. 1971 Standard.
Not only does
the garment 10' resist burning, melting or dripping when.exposed to
500°F for at least five
minutes, as does the garment 10 of Figs. 1 and 2, but the garment passes the
liquid
penetration test (ASTM test F1359), as well as all other tests comprising the
Standard. The
treatments applied to the components of the garment 10' of Fig. 3 are also
sufficiently durable
to withstand at Least 5 launderings, and preferably at least 25 launderings.
As shown in Fig. 4, in another alternate embodiment 10" of the garment of the
present invention, the moisture barner 36 is positioned adjacent to the outer
shell 26, and the
thermal liner 28 is positioned in between the moisture barrier and the face
cloth layer 34.
With this embodiment, the moisture barrier 36 protects the durable, moisture-
resistant
thermal liner 28 from liquid moisture penetrating the outer shell 26. The
advantage of
utilizing the moisture resistant thermal liner 28 of the present invention in
this embodiment is
that the moisture resistance of the thermal liner minimizes its absorption of
liquid perspiration
_7_
CA 02543728 1998-08-27
non a wearer, as wel's absorption of liquid moisture frost wicku-~g firom
sleeve and neck
openings or from a sm:~ll tear in the moisture barrier.
hurthurmare, the garment 10" ofFig. 4 meets the N.F.P.A. 1;71 Sta~-~dard. In
partic;ilar, t~~e garment 1U"' resists igniting, melting or dripping when
exposed to S~JU°F far at
least i ve minutes, passes the liquid penetration test, and passes all other
tests comprising the
Standav. While in the preferr~i farm of thz embodiment of the garment 10" the
outer shell
2f, thet~nal liner '?8 and face clath layer 24 are each treated tc~ have tlwe
durable, water-
repelient finish des; ribed with respect to the ga..rment 10, the garment 10"
can be modifiefl
such that the face cloth layer 34 is not treated with the durable finish_
"v'N~ile the forms of apparatus Il~Fel1'~ described constitute preferred
ernbodirnents of this invention, it is to be ur~derstoad that the invention is
nut limited to these
precise forms of apparatus, and that cl-~aagos nay tie made therein w~itho~lt
departing from the
c~:p~ of the invention.
_g_
