U.S. patent application number 10/387296 was filed with the patent office on 2004-01-15 for contamination avoidance garment.
This patent application is currently assigned to Kappler Safety Group. Invention is credited to Carroll, Todd R., Greene, Kathy N., Langley, John D., Vencill, Charles T..
Application Number | 20040006815 10/387296 |
Document ID | / |
Family ID | 30118230 |
Filed Date | 2004-01-15 |
United States Patent
Application |
20040006815 |
Kind Code |
A1 |
Carroll, Todd R. ; et
al. |
January 15, 2004 |
Contamination avoidance garment
Abstract
A contamination avoidance garment for emergency egress during
nuclear, biological, and chemical (NBC) events is described. The
garment is comprised of a single item, or of multiple garment
pieces, and is configured so as to afford the wearer a high degree
of barrier to a toxic environment while evacuating to a toxic free
area. The garment is designed for easy donning and doffing, and
combines the performance characteristics of both continuous
film-based barrier composites and toxic vapor adsorbing fabrics.
The garment is configured to reduce the influx of toxic chemicals
by preferentially controlling pressure differentials within the
garment by filtering the air entering various garment openings such
as sleeve-ends, neck openings, front openings, leg-openings, and/or
specifically designed environmental filtration panels.
Inventors: |
Carroll, Todd R.;
(Guntersville, AL) ; Langley, John D.;
(Guntersville, AL) ; Vencill, Charles T.; (Grant,
AL) ; Greene, Kathy N.; (Boaz, AL) |
Correspondence
Address: |
ALSTON & BIRD LLP
BANK OF AMERICA PLAZA
101 SOUTH TRYON STREET, SUITE 4000
CHARLOTTE
NC
28280-4000
US
|
Assignee: |
Kappler Safety Group
|
Family ID: |
30118230 |
Appl. No.: |
10/387296 |
Filed: |
March 12, 2003 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
60379548 |
May 10, 2002 |
|
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Current U.S.
Class: |
2/457 |
Current CPC
Class: |
A62B 17/001 20130101;
A62B 17/006 20130101 |
Class at
Publication: |
2/457 |
International
Class: |
A41D 013/00 |
Claims
That which is claimed is:
1. A contamination avoidance garment comprising a barrier fabric
that resists permeation by liquid and vapor based military chemical
agents and toxic industrial chemicals, the garment containing a
bi-directional air filtration mechanism based on sorptive materials
fitted so as to filter air that enters and exits the garment during
use.
2. The garment of claim 1, wherein the barrier fabric includes one
or more layers comprised of a thermoplastic resin selected from the
group consisting of polyvinyl chloride, chlorinated polyethylene,
chlorinated butyl, polyethylene, high density polyethylene, low
density polyethylene, linear low density polyethylene,
polypropylene, polyurethane, PTFE, combinations thereof, or
multiple-layered coextruded films which include one or more layers
of ethylene-vinyl acetate, ethylene vinyl alcohol, polyvinyl
alcohol, nylon, ionomer, or polyester.
3. The garment of claim 1, wherein the garment includes a torso
portion and limb portions, each defining primary openings in the
garment, and wherein said sorptive materials are fitted inside at
least one of the primary openings of the garment.
4. The garment of claim 3, wherein the garment includes sleeves
that form primary openings in the garment for the wearer's hands
and the sorptive materials are fitted inside these primary
openings.
5. The garment of claim 1, wherein the garment includes a neck
opening and the sorptive materials are fitted inside the neck
opening of the garment.
6. The garment of claim 1, wherein the garment includes sleeves and
the bi-directional air filtration mechanism comprises tubular arm
cuff inserts formed of adsorptive material, the tubular arm cuff
inserts being attached to the interior of the garment sleeves, and
having a constrictable opening for engaging the wearer's wrist.
7. The garment of claim 1, wherein the garment includes legs and
the bi-directional air filtration mechanism also comprises tubular
leg cuff inserts formed of adsorptive material, the tubular leg
cuff inserts being attached to the interior of the garment legs,
and having a constrictable opening for engaging the wearer's
ankle.
8. The garment of claim 1, wherein the garment includes a primary
front closure and the sorptive material is positioned behind the
primary front closure of the garment.
9. The garment of claim 8, wherein a triple storm flap which passes
ASTM F1358 is provided in the garment, the storm flap including a
first outer flap and a first inner flap, both of barrier material
and located outside the primary front closure of the garment,
further including a second inner flap of adsorptive material
located inside the closure.
10. The garment of claim 9, wherein the closure is selected from
the group consisting of a hook and loop closure, a zipper, or a
zip-lock closure.
11. The garment of claim 1, wherein the sorptive material is
comprised of a woven, nonwoven, fibrous, or foamed fabric.
12. The garment of claim 11, wherein the activity of the sorptive
material is based on either physisorption or chemisorption.
13. The garment of claim 12, wherein the sorptive material
comprises one or more adsorptive media selected from the group
consisting of activated carbon, activated carbon fibers, zeolites,
bituminous earth, porous polymers, hydrated alumina silicate,
sepiolites, silica gel, alumina, magnesia, calcium carbonate,
chlorophyll, baking soda, soda lime, calcium oxide, and potassium
permanganate.
14. The garment of claim 1, wherein the bi-directional air
filtration mechanism includes a valve body mounted in the barrier
fabric and defining a opening therethrough, and at least one layer
of adsorptive fabric mounted in the valve body across said
opening.
15. The garment of claim 14, including a cover overlying the outer
exposed surface of said valve body.
16. The garment of claim 1, wherein the bi-directional air
filtration mechanism comprises an opening formed in the barrier
fabric, and at least one layer of adsorptive fabric mounted to the
barrier fabric and extending across said opening.
17. The garment of claim 16, including a cover overlying the outer
exposed surface the adsorptive fabric.
18. The garment of claim 1, wherein the bi-directional air
filtration mechanism comprises an opening formed in the barrier
fabric, and an air-purifying cartridge or canister connected in
fluid communication with said opening.
19. The garment of claim 1, wherein, the bi-directional air
filtration system comprises one or more adsorptive media selected
from the group consisting of activated carbon, activated carbon
fibers, zeolites, bituminous earth, porous polymers, hydrated
alumina silicate, sepiolites, silica gel, alumina, magnesia,
calcium carbonate, chlorophyll, baking soda, soda lime, calcium
oxide, and potassium permanganate.
20. The garment of claim 19, wherein the bi-directional air
filtration system is in the form of a panel fabricated from
adsorptive media, said panel being disposed across an opening
formed in said barrier fabric.
21. The garment of claim 20, including a cover overlying an exposed
outer surface of said panel.
22. The garment of claim 19, wherein the bi-directional air
filtration system is in the form of one or more adsorptive disks
fitted inside a rigid or flexible pressure relief valve body, said
valve body being mounted surrounding an opening formed in said
barrier fabric.
23. The garment of claim 19, wherein the bi-directional filtration
system is in the form of a vapor adsorbent bag fitted inside the
garment.
24. A contamination avoidance garment having sleeve portions, leg
portions and a torso portion fabricated from an impermeable barrier
fabric, the garment also having at least one portion fabricated
from a permeable material that is chemically adsorptive and is
fitted so as to filter air that enters and exits the garment during
use.
25. The garment of claim 24 wherein said permeable material is an
air permeable flexible fabric material that contains one or more
adsorptive media selected from the group consisting of activated
carbon, activated carbon fibers, zeolites, bituminous earth, porous
polymers, hydrated alumina silicate, sepiolites, silica gel,
alumina, magnesia, calcium carbonate, chlorophyll, baking soda,
soda lime, calcium oxide, and potassium permanganate.
26. The garment of claim 25 wherein said at least one portion
comprises tubular sleeve inserts fabricated from said adsorptive
air permeable fabric and located within the sleeve portions of the
garment.
27. The garment of claim 25 wherein said at least one portion
comprises tubular leg inserts fabricated from said adsorptive air
permeable fabric and located within the leg portions of the
garment.
28. The garment of claim 25 which includes a neck opening adjacent
an upper end of said torso portion, and a neck collar insert
fabricated from said adsorptive air permeable fabric mounted
adjacent said neck opening.
29. The garment of claim 25 which includes a primary front closure
in the torso portion of the garment, and a triple storm flap which
passes ASTM F1358 provided along said closure, the storm flap
including a first outer flap and a first inner flap, both of
barrier material and located outside the primary front closure of
the garment, further including a second inner flap of said
adsorptive fabric located inside the closure.
30. The garment of claim 25 which includes an opening formed in the
impermeable barrier fabric, and wherein said chemically adsorptive
permeable fabric covers said opening.
31. The garment of claim 30, additionally including a valve body
mounted to the barrier fabric and covering said opening, and
wherein said chemically adsorptive permeable fabric is located
inside said valve body.
32. The garment of claim 30, including a protective flap formed of
barrier fabric and positioned adjacent said opening to serve as a
splash cover.
33. The garment of claim 24 which includes an opening formed in the
impermeable barrier fabric, and including a fitting mounted to the
barrier fabric and covering said opening, and wherein said
adsorbent material is positioned so that air entering or leaving
the garment through said opening passes through the adsorbent
material.
34. The garment of claim 33, wherein the adsorbent material
comprises one or more adsorptive disks fitted inside said
fitting.
35. The garment of claim 33, wherein the adsorbent material
comprises an adsorptive bag connected to the fitting.
36. The garment of claim 33, including a canister connected to said
fitting, and wherein the canister contains the adsorbent
material.
37. A contamination avoidance garment, said garment comprising
sleeve portions and a torso portion fabricated from an impermeable
barrier fabric, and tubular sleeve inserts fabricated from a
chemically adsorptive air permeable fabric located within the
sleeve portions of the garment.
38. The garment of claim 37 wherein the tubular sleeve inserts have
one end thereof joined to the interior of the sleeve portion of the
garment and an opposite end thereof provided with an elasticized
wrist opening.
39. The garment of claim 37 which includes a waist opening adjacent
a lower end of said torso portion, and an inner waistband insert
fabricated from a chemically adsorptive air permeable fabric
adjoining the waist opening.
40. The garment of claim 37 which includes a neck opening adjacent
an upper end of said torso portion, and an inner neck collar insert
fabricated from a chemically adsorptive air permeable fabric
adjoining the neck opening.
41. A contamination avoidance garment, said garment comprising leg
portions and a torso portion fabricated from an impermeable barrier
fabric, and tubular leg inserts fabricated from a chemically
adsorptive air permeable fabric located within the leg portions of
the garment.
42. The garment of claim 41 which includes a waist opening adjacent
an upper end of said torso portion, and an inner waistband insert
fabricated from a chemically adsorptive air permeable fabric
adjoining the waist opening.
43. The garment of claim 42 in the form of bib overalls, including
front and rear chest covering portions located above said inner
waistband formed of said barrier fabric, and suspenders carried by
said chest covering portions.
44. The garment of claim 42 in the form of trousers.
Description
CROSS-REFERENCED TO RELATED APPLICATION
[0001] This application claims priority from U.S. Provisional
Patent Application No. 60/379,548 filed May 10, 2002.
FIELD OF THE INVENTION
[0002] This invention relates generally to chemical protective
clothing and more specifically to a contamination avoidance garment
for use during nuclear, biological, and chemical (NBC) events to
allow for emergency egress.
BACKGROUND OF THE INVENTION
[0003] Millions of chemical protective garments are used each year
to protect workers from a specific hazard, or to protect the work
environment from the worker. Applications include general
maintenance activities, automotive paint spray and finishing,
pesticide application, chemical processing and manufacturing,
hazardous waste handling, treatment, and disposal, emergency
response, hospitals and EMS, pharmaceutical manufacturing and clean
room applications, military situations, and innumerable other
scenarios. The complexity of exposure scenarios combined with the
manufacturing limitations of available polymer and rubber
technologies has forced end-users to integrate various personal
protective equipment components into an ensemble that together
offers the necessary level of protection to ensure the health and
well being of the wearer.
[0004] Traditionally, protective clothing has been worn by workers
who either themselves present a risk to the work area (i.e.,
medical and clean room applications), or who may be exposed to
hazardous environments during the normal course of their work
activities (i.e., chemical processing and hazmat). The increased
threat of international and domestic terrorism has expanded the
need for protective clothing beyond traditional boundaries, and for
individuals and workplaces that in the past had no need for such
specialized equipment. This threat now includes non-traditional
targets that can hold large numbers of civilian personnel such as
airports, professional sports stadiums, large office complexes and
buildings, government facilities, and non-combative military and
quasi-military installations. The protective needs of this vast and
dynamic group of individuals is very different than what would be
considered traditional users. An effective emergency egress garment
needs to offer the user the maximum level of possible comfort, be
easily donned/doffed, sized so as to accommodate a wide array of
anthropomorphic measurements (i.e., body sizes), require a simple
training program, exhibit extended shelf-life, and offer broad
protection to a wide range of chemical, nuclear, and biological
hazards. While attempts have been made to adapt traditional
chemical protective garments, to date, no protective garment has
been designed to accommodate the unique and diverse needs of the
emergency egress market. In fact, even the industrial protective
clothing market is void of performance based standards for
evaluating the effectiveness of the vast majority of clothing
currently worn by industry.
[0005] The U.S. Environmental Protection agency (USEPA), through
their Standard Operating Guidelines, have put forth a generic
strategy for defining what they term "Levels of Protection" (LOPs).
These LOPs revolve around generic types of respiratory protection,
as defined by the Occupational Safety and Health Department (OSHA)
and the National Institute for Occupational Safety and Health
(NIOSH), and generically described chemical protective clothing,
recommended for certain chemical handling activities. The
protective clothing industry has and continues to use these
guidelines to generically describe the types of garments to be used
under various use scenarios.
[0006] Level "A" is defined as the highest level of respiratory and
chemical protection incorporating supplied air (i.e., SCBA or
airline respirator) and a fully encapsulating, gas-tight suit.
Level "A" ensembles offer the wearer protection against both
liquids and vapors. The interface between the glove and sleeve is
gas- and liquid-tight, typically consisting of a circular plastic
or metal glove-ring that is used as a form around which the glove
and sleeve are fitted and then secured with a worm-drive or
stepless ear hose-clamp. Level "A" type garments are used by highly
trained individuals in situations involving unknown chemicals and a
variety of other exposure scenarios involving high exposure
potential and carcinogenic hazards. These readily available
garments vary in price from .about.$500-.about.$3500, and are
available from a variety of manufacturers such as DuPont (USA),
Lakeland Industries (USA), Trelleborg (Sweden), Respirex (United
Kingdom), Auer (Germany), Draeger (Germany) as well as others. Base
fabrics of construction include both lightweight high-chemical
barrier composites such as Responder.RTM. (DuPont) and TyChem
10,000 (DuPont), to heavier-weight elastomers such as Viton.RTM.)
and Chlorobutyl from Trelleborg. While offering the highest level
of protection to the wearer from both the design/configuration and
fabrics of construction, Level A garments are expensive, difficult
to don/doff, require a annual inspection program, consume a fairly
large volume for the purposes of storage, and require respirator
fit testing and medical clearance on the part of the wearer prior
to use. These and additional issues make Level "A" garments
impractical for use on a large-scale as an escape garment for the
average civilian population.
[0007] The next lower level of protection described by EPA is Level
"B", which is described as requiring the same respiratory
protection as Level "A" but with a lesser degree of chemical
protection, typically not fully-encapsulating. A traditional Level
"B" ensemble includes a self-contained breathing apparatus (i.e.,
SCBA), a sealed-seam, limited-use coverall with an attached hood,
storm-flap, and attached booties, and separate chemically resistant
gloves and elastomeric over-boots. It has become common practice to
use duct-tape over the glove-sleeve and boot-leg interfaces to
minimize penetration of chemicals onto the wearer's skin and
clothing. Level "B" type garments are available from a wide variety
of manufactures fabricated from an even wider array of base
materials, both film-based and elastomeric.
[0008] One of the greatest problems with traditional Level "B"
garments, when considered for use as emergency egress garments, is
an air exchange phenomenon termed "pumping". Since the majority of
Level "B" type garments are constructed of non-air permeable,
barrier-type fabrics, air will have a tendency to "pump" in and out
of the garment through closures (i.e., zippers) and around wrists
and ankles during normal and sudden changes in the body position of
the wearer such as during kneeling, squatting, and walking. If worn
in a contaminated environment, which would be the expected use
during emergency egress during an NBC event, contaminated air could
be pulled into the garment via this "pumping" action, exposing the
wearer. While duct-tape has been used in the past on Level "B"
garments as a method of reducing the influx of chemicals through
zippers, around wrists, and around ankles, it is impractical to
require an average civilian to don a protective garment and
"tape-up" during an actual NBC emergency. The psychological stress
imposed on a civilian during times of an NBC event will be
overbearing which will require an effective protective garment to
be easy to don/doff, comfortable, inexpensive, require little
initial and sustenance training, be effectively sized so as to
accommodate the wide array of wears, as well as be easy to
maintain. Requiring a civilian wearer to don a protective garment
prior to evacuation during an NBC emergency is difficult enough.
Requiring them to tape-up that garment imposes a higher degree of
stress and complexity that can be obviated to a great extent by the
present invention. Also, since Level "B" still requires the use of
supplied air, OSHA and NIOSH require pre-use respirator training
and medical qualification.
[0009] EPA's Level "C", describes a lesser level of protection than
Level B, and includes a lower degree of respiratory protection
(i.e., air-purifying respirators), however with similar clothing
requirements as in Level "B". Since the chemical hazards and
exposures scenarios requiring Level "C" protection are less
hazardous than Level "B", "taping" is less common but still used.
Level "C" type garments are available in a variety of
configurations both one piece and multiple piece, fabricated using
a variety of protective fabrics, and incorporating several types of
seams, which all affect the ultimate protection afforded the
wearer. Unlike Level "B" garments, which are most often constructed
using a sealed seam, Level "C", garments are offered with sealed,
bounded, and simple sewn seams. Any non-sealed seam, by
construction, has the potential for allowing influx of hazardous
chemicals, thus exposing the wearer.
[0010] While Level "C" type clothing requires air-purifying
respiratory equipment, which also requires the same basic type of
testing and medical qualification as supplied air, these type
garments could be used with what OSHA and NIOSH consider
"emergency" respirators which do not require pre-use medical
clearance. Obviously "pumping" is also a major limiting factor with
traditional Level "C" garments.
[0011] Level "D" protection is the lowest level of protection
described by EPA and is used in situations where there is no risk
of respiratory exposure and very limited potential for exposure to
low hazard chemicals. Chemical protective clothing is allowable
under Level "D", however, rarely worn. Applicability of Level "D"
equipment is obviously outside the scope of the expected exposure
scenario of an emergency egress garment.
[0012] It should be evident from the above discussion, that an
immediate need exists for a garment designed specifically for
emergency egress. The present invention addresses many of the
limitations of existing protective strategies as well as the
related prior art.
[0013] An effective chemical protective ensemble can only be
designed on the basis of a detailed hazard assessment. Similarly,
selection of the most appropriate chemical protective garment on
the end-user level relies on similar information. In fact, the
United States Occupational Safety and Health Administration (OSHA),
requires that a documented hazard assessment be conducted within
the workplace to support the selection and use of any chemical
protective clothing (i.e., 29 C.F.R. 1910.132). This analysis takes
into account the expected chemical hazard(s) involved in the
situation, the probability of exposure, and the expected exposure
scenario (i.e., duration and degree). Taking this information into
account, the manufacturer can then select the appropriate materials
of construction which include fabrics and seam type, and in turn,
construct a garment that is configured such as to afford the wearer
the necessary level of protection for the expected use scenario.
Relatively controlled situations such as inspection operations on
chemical lines in a petrochemical facility will obviously require a
different type garment (i.e., fabrics, seams, and configuration)
than for an emergency responder whose scenario will be different
during each spill. Likewise, the specific needs for an emergency
egress garment must be anticipated based on a similar hazard
assessment.
[0014] Two basic technological approaches have been employed in
designing the primary materials used in the construction of
chemical protective clothing (i.e., "barrier" and "adsorption").
The majority of clothing used by general industry is based on
"barrier" technology. Barrier technology hinges on the principle
that the protective material essentially blocks the transport of a
chemical through the material. The chemical resistance of "barrier"
type materials is dictated by Fick's Law of Diffusion, and the
solubility of the chemical hazard(s) in the polymer matrix of the
protective material.
[0015] The industry standard used for evaluating chemical
resistance is the American Society for Testing and Materials (ASTM)
F739--Standard Test Methodfor Resistance of Protective Clothing
Materials to Permeation by Liquids and Gases. This method is
applicable to essentially any chemical and all chemical forms
(i.e., solids, liquids, and gases).
[0016] Numerous attempts have been made to develop chemical
protective fabrics that offer a wide range of chemical resistance
including Bartasis (U.S. Pat. No. 4,920,575), Blackburn (U.S. Pat.
No. 5,035,941), Hauer et al. (U.S. Pat. No. 5,626,947), Hendriksen
(U.S. Pat. No. 5,059,477), Langley (U.S. Pat. Nos. 4,833,010 and
4,855,178), Sahatjian et al. (U.S. Pat. No. 4,943,473), Shah (U.S.
Pat. No. 4,755,419), van Gompel (U.S. Pat. No. 4,753,419), as well
as many others.
[0017] Each of the above mentioned approaches incorporate various
types of continuous chemical barriers, and strength enhancing
substrates, scrims, and reinforcing base fabrics to achieve the
desired level of chemical resistance and physical durability. These
and other "barrier" approaches have been reduced to practice and
today make up what is termed the limited-use chemical protective
clothing market. These lightweight, cost effective garments offer a
variety of advantages including ease of hermetic heat-sealability.
Garments costing the end user under $75 have proven effective
against a wide range of chemical challenges.
[0018] While the "barrier" approach can result in a high degree of
chemical resistance, it comes at the expense of wearer comfort.
"Barrier" type fabrics resist the transport of chemicals into the
garment, and as a result, prevent the transmission of any moisture
out from the garment that is generated by the wearer. Eliminating
the body's natural thermal regulating system, evaporative cooling,
can result in rapid and serious physiological stress. Restricting
or eliminating the potential for sweat evaporation will result in
varying degrees of heat stress related illness. Practically
speaking, garments categorized as Level "B" and above are typically
designed as complete barriers to moisture transfer to ensure
adequate protection from the expected chemical exposure scenario.
As mentioned previously, "pumping" is an inherent phenomenon that
occurs while wearing garments fabricated from "barrier" type
materials, and in turn is one of the most limiting characteristics
of using such an approach for an emergency egress garment.
"Pumping" occurs at garment openings such as front closures, around
the sleeves, and boot openings, as well as at the nap of the neck,
even if the zipper closure is fully engaged. De Guzman (U.S. Pat.
No. 6,122,772), and Jones et al. (U.S. Pat. No. 4,932,078) describe
this "pumping" phenomenon in relation to the design of an effective
clean room garment. The United States Army, through the Soldier
Biological Chemical Command (SBCCOM), have quantified this
"pumping" action on various garments using the Man-In-Simulant Test
(M.I.S.T.), which is routinely used to evaluate the effectiveness
of military battle ground garments, and most recently is being used
to evaluate the performance of commercially available chemical
protective clothing in support of the domestic preparedness
objective. Testing has demonstrated that the highest concentration
of chemical contamination occurs, as expected, in the and around
the closures including the front opening, wrist, and ankles.
[0019] In contrast to the "barrier" approach of blocking chemical
transport, an alternative approach, used extensively within the
military, is termed "adsorption". "Adsorption" technology for
chemical protection as the term implies, is based on the selective
adsorption of toxic chemicals by one or more components present
within the protective fabric. Adsorption can result via
physisorption or chemisorption. This filtration-type approach is
advantageous when applied to protective clothing, in that the
fabrics offer a defined level of chemical resistance while
maintaining a relatively high degree of comfort. "Adsorption" based
materials and resulting garments, are significantly more expensive
than "barrier" type materials which limit their applicability for
widespread use as an emergency egress garment. Additionally, since
adsorption is a vapor-based phenomenon, use of these type garments
is typically limited to airborne challenges.
[0020] A significant amount of established art exists in the field
of adsorptive materials, especially in the areas of protective
clothing and filtration/respiratory materials. One of the most
widely used examples of this technology incorporates activated
charcoal that is adhered to traditional textile materials as
described by von Blucher et al. (U.S. Pat. Nos. 4,510,193,
4,677,019, and 5,277,963). Used as the primary protective material
in the U.S. military battle dress over-garment (MIL-C-29462), this
technology has been shown to be effective for its designed purpose.
Numerous other attempts have been made to incorporate "adsorption"
into various protective formats. Collier et al. (U.S. Pat. No.
5,453,314), Farnworth et al. (U.S. Pat. Nos. 4,981,738 &
5,017,424), Hart et al. (U.S. Pat. No. 4,190,696), Haruvey et al.
(U.S. Pat. No. 4,872,220), Katz (U.S. Pat. Nos. 5,162,398 &
5,614,301), Langston (U.S. Pat. No. 5,112,666), Meunier (U.S. Pat.
No. 5,221,572), Stelzmuller et al. (5,731,065), Vickers (U.S. Pat.
No. 5,678,247), etc., have used activated charcoal, or other
adsorptive media, such as silicylic acid, xerogels, xeolites, metal
oxides and hydroxides (i.e., hydrated alumina silicate), molecular
sieves, exchange resins, etc., to induce intrinsic chemical
adsorption characteristics to a fabric. Sorptive performance has
been engineered into various traditional and non-traditional woven
and non-woven fabrics and composites, foams, and fibers, which have
been further converted into various items of protective clothing.
Additional attempts have been made to induce other performance
characteristics to adsorptive fabrics such as stretch and recovery,
flame resistance, and even detoxification characteristics through
the use of surface modifying enzymes (von Blucher et al. U.S. Pat.
No. '193). The beauty of sorptive technology, and especially
activated charcoal, is its flexibility, through specialized surface
treatments, to increase and expand the chemical adsorptive
properties. Several disadvantages of traditional sorptive fabrics
as described by Langston (U.S. Pat. No. '666) and others, include,
balancing the level of sorptive loading while maximizing air flow
and resulting comfort, degradation of the charcoal due to aging of
the bonding process, shedding of charcoal through abrasion and
during conversion and normal wearing, and over loading of the
sorptive capacity by non-specific chemicals and/or high vapor and
liquid challenges. Another disadvantage of adsorptive fabrics,
especially activated charcoal, is its sensitive long-term storage
requirements. The intrinsic moisture sensitivity of activated
charcoal requires that items be sealed during storage. Since the
use of the garment of the present invention would be unexpected,
garments will most likely sit "on-the-shelf" for extended periods
of time prior to use. There is no way to readily evaluate the level
of "activity" or retained adsorption capacity of a wholly
"adsorptive" garment prior to donning. Extended storage for
film-based, "barrier" fabrics is typically not an issue.
[0021] Yet another disadvantage of "adsorptive" fabrics, when used
in emergency egress garments, are their limitation to primarily
vapor challenges, which includes water (i.e., rain). The most
common approach to improving the liquid resistance of sorptive
fabrics, is through the use of surface repellency treatments such
as Scotchgard.RTM. and Zepel-B.RTM.. While surface treatments
improve the liquid repellency (i.e., run-off) of the fabric, they
are easily overwhelmed during heavy exposures and rain events, and
cannot prevent liquid penetration while the fabric is under
physical pressure such as would occur during crawling, or that
might occur in the crutch of the arm while in movement which would
physically force the chemical through the fabric. Limitations also
exist with respect to the resistance of adsorptive fabrics to
particulate challenges such as biological hazards (i.e., anthrax).
Resistance to particulate hazards is based on a physical barrier
rather than a sorptive mode. Increases in the particulate
resistance characteristics of a sorptive material will be inversely
related to comfort.
[0022] Due to the intrinsic air-permeability of "adsorptive"
fabrics, the "pumping" phenomenon that occurs with garments
constructed using only "barrier" materials is still present,
however, to a lesser degree. Since air can move through the base
fabric, a lower pressure differential exists within the garment
which translates to less "unfiltered" air being pulled into the
garment openings such as sleeves, neck, front closure, etc.
[0023] The advantages of "barrier" type fabrics are low cost, high
and broad chemical resistance, ease of heat sealability, and
extended shelf life. Their greatest disadvantage is air/vapor
impermeability which results in "pumping", which has the potential
of exposing the wearer to contaminated air being, drawn from
outside the garment through openings such as front closures, seams,
sleeves, neck openings, etc. The advantages of "adsorptive" fabrics
are, definable chemical resistance to vapors, and air permeability.
The greatest disadvantage of "adsorptive" fabrics is their
applicability to primarily vapor challenges. The present invention
presents a novel approach to utilizing the advantageous performance
characteristics of both these protective strategies while
minimizing their aforedescribed limitations. This synergistic use
of two opposing performance characteristics manifests itself in a
protective strategy that is uniquely apposite for the complex needs
of an emergency egress garment.
[0024] It will be seen from the above teaching, that the need
exists for an effectively designed emergency egress garment that
offers the user easy don- and doff ability, is lightweight,
comfortable, exhibits extended shelf-life, and is so designed and
configured to offer a wide range of resistance to various types of
solid, liquid and vapor challenges as would exist during terrorist
events.
SUMMARY OF THE INVENTION
[0025] The present invention provides for a simple and novel
protective strategy for contamination avoidance garments that
offers adequate protection and stress relief that cannot be
achieved by prior disclosed methods, materials, concepts, or
technologies. The garment is constructed primarily of barrier type
chemical fabrics and is configured so as to cover at least the
wearer's arms, legs, and torso. The garment is constructed such
that all air that might move from outside the garment in, or
conversely inside the garment out, must first pass through a
sorptive interface.
[0026] In one embodiment, the garment comprises a barrier fabric
that resists permeation by liquid and vapor based military chemical
agents and toxic industrial chemicals, the garment containing an
air filtration mechanism based on sorptive materials fitted so as
to filter air that enters and exits the garment during use.
[0027] In a specific embodiment, the garment of the present
invention has sleeve portions, leg portions and a torso portion
fabricated from an impermeable barrier fabric. The garment also has
at least one portion fabricated from a permeable fabric that is
chemically adsorptive and is fitted so as to filter air that enters
and exits the garment during use. In certain embodiments, the
garment has tubular sleeve inserts fabricated from said adsorptive
air permeable fabric and located within the sleeve portions of the
garment. The garment may also have tubular leg inserts fabricated
from said adsorptive air permeable fabric and located within the
leg portions of the garment.
[0028] This invention is applicable to a wide variety of barrier
fabrics. As used herein, a "barrier" fabric is a material that
provides resistance to chemicals of interest, such as military
chemical warfare agents and toxic industrial chemicals, but
provides no measurable air permeability. The barrier fabric can be
totally impermeable to all materials, or can be made of a
perm-selective material that is a barrier to chemical agents of
interest but is selectively permeable to other materials, such as
water vapor, thus enhancing comfort for the wearer. Barrier fabrics
can also be made of certain monolithic breathable films or
membranes, such as Hytrel.RTM., or can be made of microporous
breathable films or membranes, such as Gore-Tex.RTM..
[0029] According to the present invention, major portions of the
garment are made from a barrier fabric, and air permeable
"adsorptive" type materials are used in certain selected areas of
the garment where air might enter or leave the garment. Ideally,
the garment will be either one-piece or multiple pieces of
separable garment items to achieve the desired level of protection.
While several embodiments will be described, a one-piece
coverall-type design is preferred for ease and speed of donning
during an emergency egress event. The desired garment is
constructed primarily of a highly chemically resistant "barrier"
material such as Zytron.RTM. 300 (Kappler, Guntersville, Ala.))
which is a bi-laminate comprising a coextruded film and a 2.0
oz/yd.sup.2 spundbonded polypropylene nonwoven web. Alternative
chemical protective fabrics that offer resistance to military
warfare agents and a wide range of toxic industrial chemicals could
also be used.
BRIEF DESCRIPTION OF THE DRAWINGS
[0030] Some of the features and advantages of the invention having
been described, others will become apparent from the detailed
description which follows, and from the accompanying drawings, in
which
[0031] FIG. 1 is a full front view of a garment in accordance with
the present invention in the form of a coverall.
[0032] FIG. 2 is a fragmentary front view of the garment of FIG. 1,
showing the triple storm-flap zippered closure.
[0033] FIG. 3 is a front view of a jacket in accordance with
another embodiment of the present invention.
[0034] FIGS. 4 and 5 illustrate further embodiments of multiple
piece garments in accordance with the present invention, these
being bib overalls (FIG. 4) and pants (FIG. 5).
[0035] FIG. 6 is a front view of another embodiment of garment in
accordance with the present invention; and
[0036] FIGS. 6A, 6B and 6C are detailed views showing several
options for flexible two-way environmental air management
mechanisms that can be fitted to an emergency egress garment such
as that shown in FIG. 6.
DESCRIPTION OF ILLUSTRATED EMBODIMENTS
[0037] The present inventions now will be described more fully
hereinafter with reference to the accompanying drawings, in which
some, but not all embodiments of the invention are shown. Indeed,
these inventions may be embodied in many different forms and should
not be construed as limited to the embodiments set forth herein;
rather, these embodiments are provided so that this disclosure will
satisfy applicable legal requirements. Like numbers refer to like
elements throughout.
[0038] The embodiment shown in FIG. 1 is a standard style coverall
including a zippered front opening, and incorporates both "barrier"
and "sorptive" fabrics. The one-piece, garment 10 is preferably
supplied to the user in a hermetically sealed package (not shown)
which is kept sealed until ready for use in order that the garment
will have extended shelf life. The one-piece coverall garment 10 is
fabricated primarily from a "barrier" type fabric 11 such as
Zytron.RTM. 300, from Kappler, Guntersville, Ala. The distal sleeve
and leg openings 12, 15 can be finished with a simple hem or may be
provided with a constrictable opening using elastic or a drawstring
or other suitable methods. The sleeve and leg openings can be
further modified with the addition of a repositionable strap 14, 17
which can further improve the overall filtration efficiency at
these openings. Adsorptive sleeve, leg, and neck collar inserts are
shown respectively as 13, 16, 18, and 19. The triple storm flap 20
is further described in connection with FIG. 2.
[0039] All seams on the garment are sewn and hermetically sealed on
the outside of the garment using seam tape as described by Langley
et al. (U.S. Pat. No. 5,169,697). Hermetic seams are preferred to
maximize the chemical resistance of the final garment, thus
preventing influx of chemical agents through holes created during
the garment assembly and sewing process. While other embodiments
could be conceived with attached hoods or other head covering
design features, the design shown in FIG. 1 will allow integration
to most known and anticipated respiratory devices, which would be
required to be worn in addition to the emergency egress garment,
described in this application.
[0040] Sorptive interface material is used in and around all areas
that would otherwise allow infiltration of potentially contaminated
air into the garment as a result of the "pumping" phenomenon
described previously. The sorptive material may comprise a woven,
nonwoven, fibrous, or foamed fabric having sorptive agents
incorporated therein. The sorptive function of the agent can be
based on either physisorption or chemisorption. Examples of
sorptive agents that can be used include one or more adsorptive
media selected from the group consisting of activated carbon,
activated carbon fibers, zeolites, bituminous earth, porous
polymers, hydrated alumina silicate, sepiolites, silica gel,
alumina, magnesia, calcium carbonate, chlorophyll, baking soda,
soda lime, calcium oxide, and potassium permanganate.
[0041] The sorptive interface used in the illustrated embodiments
was CD2610, available through Gentex Corp., Carbondale, Pa. CD2610
is an 8.9-oz/yd.sup.2 activated charcoal composite that satisfies
all of the testing criteria as detailed in the governments JSLIST
program as a 30-day overgarment. Alternative examples of adsorptive
fabric from different suppliers could also be used. An example of a
nonwoven fabric incorporating adsorptive particles is disclosed in
U.S. Pat. No. 5,952,092 and 5,972,808.
[0042] An adsorptive sleeve insert 13 of CD2610 of dimensions
approximately 12-in in length having a circumference of
approximately 14-in was fabricated and inserted into the end of
each sleeve. The adsorptive sleeve insert was constructed by sewing
together a tube of material and finishing both the proximal and
distal openings with elastic. The adsorptive insert is attached to
the garment by anchoring the proximal opening approximately 8-in up
from the distal opening of the coverall sleeve. Attachment is via a
radial sew line that is further hermetically sealed on the exterior
of the garment to prevent the penetration of any liquid challenge.
A critical path of filtration is created according to this design,
by the wearer inserting his or her hand and arm through the insert
and outer sleeve, thus extending the adsorptive insert past the
distal opening of the garment sleeve. To complete the donning
procedure, the wearer retracts the hand slightly such that an
accordion affect occurs on the adsorptive insert when the distal
elastic of the insert is brought inside the distal end of the
garment sleeve. The net effect of the accordion-type bunching and
the elastic in the proximal and distal openings of the insert is to
create a critical path for air transfer, which in effect, forces
any air "pumping" into or out of the garment sleeve to be filtered
by the adsorptive insert. The critical path concept can be further
improved upon by adding additional elastic to the distal opening of
the garment sleeve, or by adding a repositionable Velcro.RTM. wrist
strap that can be engaged radially around the wrist thus further
compressing the adsorptive insert. A similar approach can be used
to fabricate leg cuff inserts 16 in the leg openings, however with
different dimensions. It should be evident that other designs could
be conceived to accomplish the same net effect of filtering air
through an adsorptive media placed at the sleeve and leg
openings.
[0043] Two remaining sensitive areas that can contribute to
contamination as a result of "pumping" are around the neck and the
front opening on a coverall, and around the waist of a jacket,
pant, or bib overall. Since emergency egress situations must be
anticipated under all conditions, contributory environmental
influences must be considered. In the extreme, an evacuation can be
anticipated through a liquid challenge and while during a rain
event. This combination would result in failure of most wholly
sorptive garments, if nowhere else except through the sewn seams.
The garments of the present invention present a front closure that,
when used in combination with a hermetically sealed seam will pass
liquid-tight integrity test (i.e., shower test) as described by
ASTM F1358. This test exposes a garment to a deluge of
surfactant-treated water via 5 showerheads. The garment is mounted
on a mannequin and the mannequin is incrementally rotated through
360.degree.. A reasonable exposure duration for emergency egress
purposes is 20 minutes, such as is specified in the National Fire
Protection Association (NFPA) NFPA 1992--Standard on Liquid
Splash-Protective Suits for Hazardous Chemical Emergencies.
Traditional garments such as the Level B garments described above
could not pass the shower test without modification with duct-tape.
The garment of the present invention can pass the test since it is
fitted with a triple storm-flap which includes a first outer flap,
and first inner-flap, a traditional cloth zipper, and a second
inner flap/placate that is positioned inside the zipper and in this
embodiment, is a double-layer of the CD2610 adsorptive fabric. The
first outer and first inner storm-flaps are removably attached via
a full length of a hook and pile closure such as Velcro.RTM.. This
closure will repel any liquid exposure, and has the added benefit
of filtering air that is pushed from outside the garment or that
might be drawn in through the closure.
[0044] The final entry point for contaminated air is through the
head opening and around the neck. The present invention improves
upon existing approaches by adding an optional circular inner
collar insert 18 of adsorptive material. The sorptive neck insert
18 is positioned perpendicular to the neck and is finished on the
exposed edge with elastic.
[0045] The insert extends beyond the end of the collar and onto the
second inner storm-flap to ensure that the entire neck is encircled
by the sorptive insert. Additional adsorptive material 19 can be
placed on the interior of a mandarin-type collar, which will
further serve to reduce any vapor threat by scavenging present
airborne challenges. Additionally, an inner collar-collar can be
added to the insert, preferable fabricated from elasticized
sorptive material that would act more like a turtleneck. Additional
security can be added by fitting the collar with a repositionable
strap such as was described above for use around the wrist and
ankles.
[0046] Similar approaches to the neck closure can be incorporated
into the waist of multi-piece garments such as jackets, pants, and
bib overalls, as shown in FIGS. 3, 4 and 5.
[0047] FIG. 2 shows the triple storm-flap zippered closure that
enables passage of ASTM F1358. This closure can be used on single
and multiple piece garments such as coveralls and jackets. The
outer storm-flap 20 is fitted with the loop portion 22 of the
repositionable hook and loop fastener. The second outer storm-flap
21 is fitted with the hook portion 23 of the repositionable hook
and loop fastener. The cloth zipper 27 is further backed by a
double-layer sorptive inner storm-flap 24. The sorptive neck insert
that encases the wearer's neck is indicated at 25. An additional
layer 26 of sorptive material is provided on the interior of the
mandarin collar.
[0048] FIG. 3 illustrates a jacket 30 that incorporates either
hemming or elastic at the distal sleeve opening 32, or a
repositionable strap 34, that can be engaged over the adsorptive
sleeve insert 33. A waist insert 35 formed of adsorptive material
is provided along the waistband of the jacket extending inwardly to
engage the wearer's waist. The waist insert is thus arranged to
filter any air that may enter or leave the jacket from the waist
area. The waist insert 35 is attached to the jacket waistband along
its outer periphery has an inner periphery which is made
constrictable, e.g. by an elastic hem, to snugly engage the waist
The jacket has the same configuration of a triple storm-flap 36 and
adsorptive neck insert 37 as is disclosed in FIG. 2.
[0049] FIGS. 4 and 5 show further embodiments of multiple piece
components, these being bib overalls (FIG. 4) and pants (FIG. 5).
FIG. 4 discloses a bib overall 40, constructed primarily of the
barrier material 41, incorporating either a hem or elastic at the
distal leg opening 42. These bib overalls also include an
adsorptive leg insert 43 of the type previously described, and a
repositionable strap, 44, as well as an adsorptive upper waist
insert 45. The waist insert 45 is attached along its outer radius
to the barrier fabric 41, such as by sewing, and has a
constrictible inner radius formed by elastic, a drawstring or other
suitable arrangement. Similarly, FIG. 5 discloses pants 50
fabricated from a barrier material 51, including a hemmed or
elasticized distal leg opening 52, an adsorptive leg insert, 53,
and an optional repositionable strap 54. An adsorptive waist insert
56 is positioned close to the primary opening 55 which can
incorporate elastic, drawstring, or other closure that is common in
the industry.
[0050] Since it may be preferred to construct an emergency egress
garment with attached boots and gloves, as well as a liquid and/or
vapor tight closure, an alternative method for managing "pumping"
may be required. The present invention also provides a novel
flexible bi-directional air exchange mechanism that effectively
releases heat and moisture that may build-up inside the garment,
yet filters any incoming air that might be contaminated. This
required bi-directional valving cannot be accomplished using
traditional uni-directional valves that are common in gas-tight
Level A garments. These valves have been borrowed from the
air-purifying respiratory market and are typically used behind a
filter cartridge. In a respirator, air is brought through the
filter cartridge or canister and into the mask for inhalation by
the wearer, a flapper valves closes the cartridge passage and
exhaled air exists through a second one-way valve. This
unidirectional flow is effective for respiratory equipment but
inadequate for an emergency egress garment since the present
invention attempts to filter air that infiltrates the garment as a
result of "pumping". Three such approaches are described herein,
however others could be anticipated. The first utilizes a typical
valve body that is fitted in the garment. In place of the one-way
flapper valve, multiple rings of adsorptive fabric can be inserted
within the valve body thus creating a critical path of adsorptive
media through which any air must flow when entering or exiting the
garment. Greater filtering efficiency can be achieved using thick
layers of sorptive fabric. An exterior exhaust cover fabricated
from the "barrier" material is also preferred to shed any liquid
that might come in proximity of the exhaust port.
[0051] An alternative approach for managing potentially
contaminated air flow into a garment is to fit either single or
multiple layers of sorptive fabric over an opening in the garment,
which has the same net effect as the valve body inserts. The
sorptive material can be attached to the interior of the garment
according to several different techniques including adhesives,
heat-sealing within a barrier fabric frame/enclosure or other
means. Again it is preferred to incorporate single and or double
exterior exhaust covers to minimize liquid contact of the sorptive
media.
[0052] A third approach to creating a flexible bi-directional air
exchange mechanism is to provide a fitting in the form, for example
of a valve body, that surrounds an opening formed in the barrier
fabric. Various configurations of adsorptive inserts can be
connected to the fitting or valve body. For example, the valve body
can be connected to a secondary air infiltration bag not unlike a
disposable vacuum cleaner bag. In this case, a bag is fitted around
the interior of the valve body and is either constructed of or
contains adsorptive media. The principle here again is to force any
air through the sorptive media which in turn offers the wearer a
high degree of comfort since heat and perspiration can exit the
garment, and contaminated air is filtered through the sorptive
inserts.
[0053] One final approach for bi-directional airflow management
that is especially suited for garments that maybe more
encapsulating in design (i.e., those incorporating attached hood,
gloves, boots, and liquid- or gas-proof closures), is to modify the
operation of traditional unidirectional air-purifying respirator
cartridge/canister systems. One or more air-purifying respirator
cartridges/canisters can be mounted in the garment without the use
of or including the unidirectional flapper valve that is most often
removably mounted in the cartridge mounting body. An NBC approved
cartridge or canister is best suited for this application. The
convention of use will allow free airflow through the cartridge or
canister. The present invention can accommodate a variety of
"barrier" and "sorptive" fabrics, as well as alternative flexible
2-way air exchange mechanisms.
[0054] FIG. 6 shows several options for flexible two-way
environmental air management mechanisms that can be fitted to an
emergency egress garment, 60. FIG. 6A illustrates use of a typical
valve body 64 that has been fitted with one or more adsorptive
disks 65. The valve body includes a rigid cap 62, which offers
physical protection to the adsorptive media, the entire ensemble of
which is set in the barrier fabric, 63, and further covered with an
additional layer of barrier fabric 61 in the form of a protective
flap that acts as a splash-cover. FIG. 6B shows an alternative
embodiment that utilizes a layer of the adsorptive materials 69
that has been adhered to the inside the garment and barrier fabric
68, and further covered by overlapping upper and lower protective
flaps 66, 67 serving splash-covers. FIG. 6C discloses yet another
embodiment that incorporates a valve body 73 that holds an
adsorptive bag 74, the valve body of which is covered by a rigid
cover 72, and set in the barrier fabric 70. The entire valve system
is further covered by the splashguard 71.
[0055] The filter efficiency of the bi-directional air management
system can be controlled with variable loading levels of the
adsorptive component, and/or multiple separate layers, or
configurations of the adsorptive fabric. The bi-directional air
filtration mechanism is comprised of one or more air purifying type
respiratory cartridges or canisters.
[0056] Many modifications and other embodiments of the inventions
set forth herein will come to mind to one skilled in the art to
which these inventions pertain having the benefit of the teachings
presented in the foregoing descriptions and the associated
drawings. Therefore, it is to be understood that the inventions are
not to be limited to the specific embodiments disclosed and that
modifications and other embodiments are intended to be included
within the scope of the appended claims. Although specific terms
are employed herein, they are used in a generic and descriptive
sense only and not for purposes of limitation.
* * * * *