U.S. patent application number 11/425977 was filed with the patent office on 2007-05-03 for safety outerwear with fire resistant mesh.
This patent application is currently assigned to SAFETY-SHORT WORKWAIR INC.. Invention is credited to James Barry SILVER.
Application Number | 20070094763 11/425977 |
Document ID | / |
Family ID | 37994362 |
Filed Date | 2007-05-03 |
United States Patent
Application |
20070094763 |
Kind Code |
A1 |
SILVER; James Barry |
May 3, 2007 |
SAFETY OUTERWEAR WITH FIRE RESISTANT MESH
Abstract
An article of safety outerwear has a main body piece that
receives a portion of the body of a wearer in use. The main body
piece includes a garment wall that defines inside and outside wall
portions. The inside wall portion presents a smooth surface to the
body of the wearer in use. The outside wall portion is adapted for
constant exposure to environmental conditions and to protect
against abrasion during working and/or athletic activity. The
garment wall is formed at least in part from a vent portion, such
that at least a portion of each of the inside and outside wall
portions is defined thereby. The vent portion is constructed solely
from one or more layers of a mesh material, and is safety rated
with a flame resistant rating qualifying same for flame resistant
use in hazardous environments. The mesh material operatively has an
open texture for high breathability.
Inventors: |
SILVER; James Barry;
(Dundas, ON) |
Correspondence
Address: |
LANG MICHENER LLP
BCE PLACE
SUITE 2500, 181 BAY STREET
TORONTO
ON
M5J 2T7
CA
|
Assignee: |
SAFETY-SHORT WORKWAIR INC.
701 York Road
Dundas
ON
|
Family ID: |
37994362 |
Appl. No.: |
11/425977 |
Filed: |
June 22, 2006 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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10834941 |
Apr 30, 2004 |
7181774 |
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11425977 |
Jun 22, 2006 |
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10231069 |
Aug 30, 2002 |
6968573 |
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10834941 |
Apr 30, 2004 |
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60692565 |
Jun 22, 2005 |
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Current U.S.
Class: |
2/69 |
Current CPC
Class: |
A41D 27/28 20130101;
A62B 17/003 20130101; A41D 13/00 20130101; A41D 2600/202
20130101 |
Class at
Publication: |
002/069 |
International
Class: |
A41D 13/00 20060101
A41D013/00 |
Claims
1. An article of fire resistant safety outerwear comprising a main
body piece adapted to receive in encompassing relation at least a
portion of the body of a wearer in use, wherein the main body piece
comprises a garment wall that defines an inside wall portion and an
outside wall portion, with said inside wall portion being adapted
to present a substantially smooth surface to the body of the wearer
in use, and with said outside wall portion being adapted for
substantially constant exposure to environmental conditions and to
provide the wearer with protection against abrasion during normal
activity selected from the group consisting of working activity and
athletic activity; with said garment wall being formed at least in
part from a vent portion, such that at least a portion of each of
said inside wall portion and said outside wall portion of said
garment wall is defined by said vent portion; with said vent
portion being constructed solely from at least one layer of a mesh
material, with said vent portion being safety-rated with a flame
resistant rating that qualifies said vent portion for flame
resistant use in hazardous environments, and with said mesh
material operatively having a substantially open texture for high
breathability.
2. An article according to claim 1, wherein a substantial entirety
of said garment wall is formed from said vent portion.
3. An article according to claim 1, wherein said mesh material is
constructed at least in part from a synthetic flame resistant
material.
4. An article according to claim 3, wherein said synthetic flame
resistant material comprises a synthetic flame resistant fiber that
is characterized by low stiffness and high elongation, so as to
provide textile-like characteristics, and so as to enable
processing of said fiber on conventional textile equipment.
5. An article according to claim 3, wherein said synthetic flame
resistant material comprises one or more fibers selected from the
group consisting of aromatic polyamide fibers, para-aramid fibers,
meta-aramid fibers, polyamide-imide fibers, polybenzimidazole
fibers, celazole fibers, melamine fibers, oxidized
polyacrylonitrile fibers, and modacrylic fibers.
6. An article according to claim 1, wherein said mesh material is
constructed at least in part from a natural material.
7. An article according to claim 6, wherein said natural material
comprises a material rendered flame resistant by surface treatment
with a flame retardant chemical.
8. An article according to claim 6, wherein said natural material
comprises a natural fiber rendered flame resistant by impregnation
of a flame retardant chemical into a substantial core thereof.
9. An article according to claim 1, wherein said mesh material is
selected from the group consisting of flame resistant perforated
fabrics, flame resistant lattice-type fabrics, and flame resistant
open-work fabrics.
10. An article according to claim 1, wherein said flame resistant
rating comprises char length values, afterflame values, and
afterglow values compliant with the vertical flame test under
Method 5903.1 of United States Federal Standard 191A.
11. An article according to claim 1, wherein said flame resistant
rating comprises char length values, afterflame values, and
afterglow values compliant with the vertical flame test in
accordance with the American Society for Testing and Materials
D-6413 standard.
12. An article according to claim 1, wherein said flame resistant
rating comprises an arc thermal performance value rating
substantially within the range of between about a 0.1 rating and
about a 5.0 rating, and wherein said flame resistant rating further
comprises a hazard/risk category rating substantially within the
range of between about a 0.1 rating and about a 1.0 rating.
13. An article according to claim 1, wherein said flame resistant
rating comprises an arc thermal performance value rating
substantially greater than about a 5.0 rating, and wherein said
flame resistant rating further comprises a hazard/risk category
rating of substantially greater than about a 1.0 rating.
14. An article according to claim 1, wherein said flame resistant
rating comprises a rating compliant with the National Fire
Protection Association 2112 standard.
15. An article according to claim 1, wherein said mesh material has
an actual weight of substantially about 6.0 ounces per square yard,
and wherein said flame resistant rating comprises a thermal
protective performance rating of substantially greater than about
6.0 calories per square centimeter, with said thermal protective
performance rating obtained in accordance with the American Society
for Testing and Materials D-4108 standard.
16. An article according to claim 1, wherein said mesh material
retains a high visibility dye.
17. An article according to claim 1, wherein said main body piece
includes: a trunks outerwear part, adapted to receive in
encompassing relation the lower region of the torso of a wearer in
use and having apertures through which the legs of said wearer
protrude in use; and a pair of tubular leg parts, each adapted to
receive therethrough a respective protruding leg of said wearer in
use and extending between a respective upper end, connected to said
trunks outerwear part, and a respective lower end, disposed
adjacent to the ankle of said respective protruding leg, wherein
one said vent portion is provided in each leg part as a tubular
vent portion, extending, with respect to the respective protruding
leg received in said each leg part in user from about mid-leg to
about the ankle.
18. An article according to claim 17, wherein said main body piece
is trouser outerwear.
19. An article according to claim 1, wherein said main body piece
includes: a trunks outerwear part, adapted to receive in
encompassing relation the lower region of the torso of a wearer in
use and having apertures through which the legs of said wearer
protrude in use; a pair of tubular leg parts, each adapted to
receive therethrough a respective protruding leg of said wearer in
use and extending between a respective upper end, connected to said
trunks outerwear part, and a respective lower end, disposed
adjacent to the ankle of said respective protruding leg; and a bib
part securely attached to the trunks outerwear part; wherein said
bib part, said trunks outerwear part, and said leg parts together
forming a bib overall; and with at least one said vent portion
being provided in said bib overall.
20. An article according to claim 1, wherein said main body piece
includes: a trunks outerwear part, adapted to receive in
encompassing relation the lower region of the torso of a wearer in
use and having apertures through which the legs of said wearer
protrude in use; a pair of tubular leg parts, each adapted to
receive therethrough a respective protruding leg of said wearer in
use and extending between a respective upper end, connected to said
trunks outerwear part, and a respective lower end, disposed
adjacent to the ankle of said respective protruding leg; and a
front closure jacket part securely attached to said trunks
outerwear part; wherein said jacket part, said trunks outerwear
part, and said leg parts together forming a coverall; and with at
least one said vent portion being provided in said coverall.
21. An article according to claim 1, wherein said main body piece
comprises: an upper torso outerwear part, adapted to receive in
encompassing relation the upper region of the torso of a wearer in
use and having apertures through which the arms of said wearer
protrude in use; and a pair of tubular arm parts, each adapted to
receive therethrough a respective protruding arm of said wearer in
use and extending between a respective upper end, connected to said
upper torso outerwear part, and a respective lower end, disposed in
a wrist-ward direction from said respective upper end along said
respective protruding arm; with at least one said vent portion
being provided in at least one of said upper torso outerwear part
and said arm parts.
22. An article according to claim 21, wherein said upper torso
outerwear part is shaped to define a front opening, and wherein
said upper torso outerwear part comprises a front-closure means for
securing said front opening of said upper torso outerwear part in a
closed configuration.
23. An article according to claim 1, further comprising a covering
shell substantially secured to said main body piece for covering
said vent portion, with said covering shell adapted to be turned
back from said vented portion into an opened configuration, wherein
said covering shell is selectively securable in said opened
configuration by securement means affixed to said main body
piece.
24. An article according to claim 1, further comprising a covering
shell detachably secured by securement means affixed to said main
body piece for covering said vent portion.
25. An article according to claim 24, wherein said covering shell
is constructed of a fabric material of substantially closed
texture.
26. An article according to claim 25, wherein said fabric material
is formed at least in part from a high temperature flame resistant
petrochemically-based manufactured fiber.
27. An article according to claim 25, wherein said fabric material
is formed at least in part from a natural fiber rendered flame
resistant by a process selected from the group consisting of
surface treatment with a flame retardant chemical, and impregnation
of a flame retardant chemical into a substantial core thereof.
28. An article according to claim 1, wherein said main body piece
includes a pocket means for temporarily storing items during a
normal activity selected from the group consisting of workplace
activities and athletic activities; and wherein said pocket means
comprises at least one pocket that is sized to receive and store a
covering shell which is detachably securable to said main body
piece for covering said vent portion.
29. An article according to claim 1, further comprising a pair of
pads attached to said main body piece to cover a first pair of body
parts of said wearer in use, with said first pair of body parts
being selected from the group consisting of a pair of knees and a
pair of hips of said wearer.
30. An article according to claim 29, wherein said pads are
removably attached to said main body piece.
Description
FIELD OF THE INVENTION
[0001] The present invention relates to the field of safety
clothing, and more particularly, at least to the use of
open-textured materials and fabrics in secondary flame resistant
garments that satisfy the safety standards for workers exposed to
risks of flash fires and/or electrical arc hazards.
BACKGROUND OF THE INVENTION
[0002] Each and every day, workers in the electrical maintenance,
Utilities, oil, gas, petrochemical and steel industries work in
environments that may expose them to hazards that could cause
severe and/or fatal burn injuries. In the event of a momentary
electric arc, flash fire, and/or molten metal splash exposure,
standard work clothes that are not flame resistant may ignite and
may continue to burn even after the source of ignition has been
removed. Untreated natural fabrics may continue to burn until the
fabric is totally consumed. Synthetic fabrics that are not flame
resistant will also burn, with melting and dripping causing severe
contact burns to the skin. In fact, various government reports may
note that the vast majority of severe and/or fatal burn injuries
may be due to the ignition and/or continued burning of an
individual's clothing, and possibly not to exposure to the source
of ignition itself.
[0003] Perhaps as a direct result, Occupational Safety and Health
Administration (OSHA) regulations, American Society for Testing and
Materials (ASTM) standards, National Fire Protection Association
(NFPA) recommendations, and corporate safety guidelines may have
encouraged, the adoption or flame resistant clothing for worker
protection where a flash fire and/or electric arc hazard may be
identified. In the prior art, chemical, petrochemical, and/or
utility workers may have worn flame resistant clothing as a
protective barrier against the intense neat from flash fires and
electric arcs, and possibly to give such wearers a few extra
seconds of escape time. Shirts, pants, coveralls, sweatshirts, rain
wear, insulated all-season coveralls and coats may be commonly
constructed using flame resistant materials. Other end users of
flame resistant clothing in single and/or multi-layered
configurations may include welders, firefighters, race car drivers
and their crews, as well as the military, NASA astronauts, and
rocket fuel handlers.
[0004] ASTM Standard F1.002, which is incorporated herein by
reference, bears the title "Standard Performance Specification for
Protective Clothing for Use by Workers Exposed to Specific Molten
Substances and Related Thermal Hazards", and its Abstract reads at
least in part as follows: [0005] "1.1 This performance
specification covers textile materials to be used for protective
clothing. [0006] "1.2 Materials used for both primary protection
and for secondary protection are covered. [0007] "1.3 Protective
properties relate to contact with molten substances and hot
surfaces, and exposure to open flame and radiant heat. [0008] "1.4
This performance specification covers clothing design
characteristics that relate to the unique protective requirements
of working with molten substances. [0009] "1.5 This performance
specification describes the properties of specific textile
materials in their fabric or garment composite form as tested by
laboratory methods and is not intended to be used to appraise the
thermal hazard or fire risk under actual conditions. However,
information on the thermal performance of clothing made from
textile materials conforming to this specification may be used as
an element in thermal risk assessment which takes into account all
factors pertinent to the thermal hazard of a particular end use."
As may be generally and/or specifically defined in ASTM Standard
F1002, flame resistant clothing may be generally divided into two
or more distinct categories depending upon the application for
which it is intended, namely, as follows: (i) primary protective
clothing, and/or (ii) secondary protective clothing.
[0010] Primary protective clothing may be used when an employee may
conduct tasks in a workplace where significant exposure to molten
substance splash, radiant heat and/or flame may be likely to occur.
Typically, these garments may have a heavier and/or multi-layer
construction, and may be worn as a temporary outer layer of
clothing (hereinafter, alternately referred to as "outerwear")
which may be put on over top of existing clothing before entering
an environment that may have known hazardous conditions, and which
may then be removed after completing a required task. Not unlike
common safety eyeglasses, primary protective clothing may generally
be considered standard occupational Personal Protective Equipment,
or PPE, and may generally tend to be task specific. Firefighter
turnout gear may comprise one such example.
[0011] Secondary protective clothing may be designed for continuous
wear as outerwear that may or may not be put on over top of other
clothing. For example, this category of protective clothing may
include apparel such as shirts, pants, and/or coveralls for
designated work areas where intermittent exposure to heat, flame
and/or molten substance may be possible. The flame resistant
secondary protective garments may generally have a single layer
construction and/or may be intended to provide the wearer with
immediate thermal protection from the flash fire, electrical arc
flash, and/or molten metal splash at the exposure area. As well,
secondary protective garments may be constructed using fabrics with
acceptable char length, afterflame and afterglow values according
to the Vertical Flame Test (Federal Standard 191A, Method 5903.1
which, after the source of ignition may be removed, may not
continue to burn and/or which may help to limit the overall body
burn percentage which may be suffered by the wearer.
[0012] From the perspective of an individual worker and/or a
company's purchasing manager, the best flame resistant clothing
purchase may ideally consist of garments that may be comfortable
and/or offer the highest level of protection to numerous types of
hazards. Also, most purchasing managers may generally agree that
one of the most critical indicators of the success of a workplace
protective apparel program may not necessarily reside in the
protection offered by their flame resistant clothing. Rather,
success may often be measured by the level of acceptance that the
protective clothing may receive from the workers who may use the
clothing on a daily basis, possibly without supervision and/or
complaints about poor garment comfort, fit and/or style.
Unfortunately, comfort and protection may long have been perceived
to be mutually exclusive when it comes to flame resistant work
clothing. Conventional thinking may have taught, perhaps more so
than any other factor, that thermal protection may be largely a
function of the thickness of an un-breached and/or non-permeable
barrier between a wearer and a hazard. Also, the level of
protection may generally have been thought to result from fabric
composition, and/or the level of protection may have typically been
thought to increase with higher fabric weights. Since higher fabric
weights and/or thicknesses, combined with a general lack of
breathability in a tightly woven fabric texture, may be commonly
associated with poor comfort, it may not have been easy, in the
prior art, to find protective clothing with both the highest level
of protection and comfort, offered in the same garment,
particularly as the issue of comfort may relate to worker heat
prostration issues. As a result, managers and/or purchasers may
long have struggled to find an acceptable balance between the two
in the prior art, and manufacturers may even have taken tremendous
steps to provide garment choices that are softer, lighter in
weight, more breathable, and/or more comfortable.
[0013] Further, in hot environments, persons may often wish to wear
shorts, also known as knee breeches, and/or other highly breathable
and/or exposing articles of clothing, possibly for comfort as an
outer layer of clothing. However, knee breeches and/or such other
breathable and/or exposing articles of clothing may not constitute
suitable apparel in circumstances wherein, inter alia, there is a
risk of momentary electric arc, flash fire, and/or molten metal
splash exposure, and/or where the knees of persons wearing such
apparel may be apt to come into contact with rough surfaces.
Indeed, and as aforesaid, in many such settings, applicable
legislation may prohibit the use of knee breeches and/or other such
potentially exposing articles clothing. Moreover, in some
environments, temperatures may plummet significantly, possibly in a
relatively short period, in which case, persons wearing shorts
and/or other exposing articles of clothing as an outer layer of
clothing may become uncomfortably cool.
[0014] The prior art may be replete with examples of jackets which
may be removed and/or long pants which may be adapted to be worn as
an outer layer of clothing and which include legs that may be
removed from the knee down, thereby to possibly convert into an
outer layer of knee breeches and/or other exposing clothing, and/or
the reverse. U.S. Pat. No. 269,479 (Stretch et al.), issued Dec.
19, 1882, may be exemplary in this regard.
[0015] Such clothing articles may be beneficial in that, in hot
environments, the clothing may normally be worn with the leg
portions and/or other covering portions removed, and/or in
circumstances when the wearer anticipates that his or her knees,
lower legs, and/or other exposed body portions may come into
contact with a momentary electric arc, flash fire, and/or molten
metal splash exposure and/or rough surfaces, the leg portions
and/or other covering portions may be reinstated, possibly for
safety. However, in circumstances when the wearer may not be able
to anticipate when his or her lower legs and/or other exposed body
portions may be exposed to injury, convertible trousers and/or
other convertible clothing represents no particular advantage,
since, possibly for safety, the wearer may be mandated to wear the
clothing with the leg portions and/or other covering portions in
place at all times, possibly with consequent discomfort.
[0016] By way of providing a further background of the invention,
impregnated flame resistant fibers in the prior art may have
undergone a process whereby flame retardant chemicals became
permanently infused within the cotton and/or other natural fibers
themselves. Such treated natural fibers may have been previously
used in combination with aramids and/or modacrylics as well. The
INDURA.RTM. Ultrasoft fabric which is manufactured by Westex Inc.,
of Chicago, Ill., is a flame resistant cotton,/synthetic blend. The
cotton in the INDURA.RTM. Ultrasoft fabric is impregnated to the
core with a flame retardant chemical. It may be generally believed,
though not essential to the present invention, that the INDURA.RTM.
Ultrasoft fabric offers protection with the comfort and
affordability of cotton. The INDURA.RTM. Ultrasoft fabric may have
industrial applications and may provide effective protection
against potential risks associated with welding and similar
activities. The INDURA.RTM. Ultrasoft fabric may retain the
beneficial properties of natural cotton for wearer comfort and
absorbency. The LENZING FR.RTM. fiber is a natural fiber that is
derived from wood and/or a natural raw material. LENZING FR.RTM.
fiber is provided with a flame retardant substance incorporated
throughout the cross-section of the fiber, which protective
substance cannot be removed by washing and/or abrasion.
[0017] On the other hand, in the prior art, flame resistant
"surface-treated" fabrics and/or fibers may be mainly
distinguishable from other natural fabrics and/or fibers by virtue
of fire retardant chemicals having been applied to the surface of
the material or to the surface of the fibers themselves. The
resulting flame resistance afforded to the fabric and/or fiber in
this manner may generally not have been a permanent feature, and/or
it may have washed out and/or have been worn off. An exemplary
prior art fabric and/or fiber in this regard may be the PROBAN.TM.
fabric and/or fiber manufactured and/or distributed by Rhodia.
[0018] In the prior art, aramids may generally have included, among
other thins, NOMEX.RTM., KEVLAR.TM. and TWARON.TM. fibers and/or
fabrics--the last-mentioned one actually being a para-aramid nylon.
NOMEX.RTM., KEVLAR.TM. and TWARON.TM. are trademarks of DuPont.
DuPont's NOMEX.RTM. IIIA aramid is a fabric that may have generally
consisted of 93% NOMEX, 5% KEVLAR, and 2% carbon. Carbon may have
been in NOMEX.RTM. IIIA fabric to reduce and/or dissipate static.
Though not essential to the invention, it may be generally
believed. A that DuPont's NOMEX.RTM. IIIA aramid possesses the
following characteristics, among others: (i) it may be an
inherently flame resistant anti-static fabric engineered to reduce
"nuisance" static; and (ii) it may be self-extinguishing, and may
not ignite melt, drip, and/or burn. Again, though it is not
essential to the invention, these characteristics may be generally
thought to make NOMEX.RTM. fabrics exceptional all-around fabrics
for applications such as petroleum refining, petro-chemical, fire
service, and/or gas and/or electric utilities. Though not essential
to the invention, DuPont's prior art KEVLAR.TM. aramid fiber and/or
fabric may be generally thought to be a strong ballistic
flame-resistant material. In the prior art, KEVLAR.TM. fibers may
have been used in chain saw protective pants and/or in other
forestry applications, and/or in bullet proof vests, etc.
[0019] In the prior art, many textile manufacturers may generally
have tended to use combinations or cottons, aramids and/or other
synthetics. Over and above aromatic polyamides (or aramids), and
though not essential to the invention, synthetic fibers and/or
fabrics may have also included para-aramids, meta-aramids,
polyamide-imides, polybenzimidazoles (PBI), celazoles, melamines,
oxidized polyacrylonitriles and/or modacrylics. Synthetics may be
petroleum-derived and/or man-made fibers. PBI is a heat and flame
resistant fiber that may have a multitude of high temperature
applications. Celazole is a family of high temperature PBI polymers
that may be available in true polymer form. Basofil.RTM. fibers may
be included in the general class of melamine fibers, which are heat
and flame resistant fibers. Modacrylic fibers may have been the
first flame resistant synthetic fibers, and it is generally
believed, though not essential to the present invention, that they
do not support combustion, are self-extinguishing, and do not
drip.
[0020] By way of providing a still further background of the
invention, ASTM document D3217-01a, which is incorporated herein by
reference, is entitled "Standard Test Methods for Breaking Tenacity
of Manufactured Textile Fibers in Loop or Knot Configurations".
This ASTM document may be considered relevant to assessing whether
particular fibers may be considered to have a high elongation.
[0021] ASTM document D3822-01, which is also incorporated herein by
reference, is entitled "Standard Test Method for Tensile Properties
of Single Textile Fibers". This ASTM document may be considered
relevant to assessing the tensile properties of particular fibers.
Its abstract reads, at least in part, as follows: [0022] "1.1 This
test method covers the measurement of tensile properties of natural
and man-made single textile fibers of sufficient length to permit
mounting test specimens in a tensile testing machine."
[0023] ASTM document D1388-96(2002), which is still further
incorporated herein by reference, is entitled "Standard Test Method
for Stiffness of Fabrics". This ASTM document may be considered
relevant to assessing whether particular fabrics and/or clothing
items may be considered to have a low stiffness. Its abstract
reads, at least in part, as follows: [0024] "1.1 This test method
covers the measurement of stiffness properties of fabrics. Bending
length is measured and flexural rigidity is calculated."
[0025] Though American Association of Textile Chemists and
Colorists (AATCC) Test Method 124-2005--which is similarly
incorporated herein by reference and is entitled "Appearance of
Fabrics after Repeated Home Laundering"--describes smoothness after
repeated home launderings, this document may be helpful to define,
with any such variations as may be necessary in the context, what
may be meant by the phrase a "substantially smooth surface". Its
abstract reads, at least in part, as follows: [0026] "1.1 This test
method is designed to evaluate the smoothness appearance of flat
fabric specimens after repeated home laundering. [0027] 1/2 Any
washable fabric may be evaluated for smoothness appearance using
this method. [0028] "1.3 Fabrics of any construction, such as
woven, knit and nonwoven, may be evaluated according to this
method."
[0029] ASTM document D3886-99(2006), which is also incorporated
herein by reference, is entitled "Standard Test Method for Abrasion
Resistance of Textile Fabrics (Inflated Diaphragm Method)". This
ASTM document may be considered relevant to assessing whether
particular fabrics and/or clothing items may be considered to offer
protection against abrasion. Its abstract reads, at least in part,
as follows: [0030] "1.1 This test method covers the determination
of the resistance to abrasion of woven and knitted textile fabrics,
both conditioned and wet, using the inflated diaphragm tester. This
procedure is not applicable to floor coverings." Of course, other
procedures for measuring the abrasion resistance of textile fabrics
are given in ASTM Test Methods D 3884, D 3885, D 1175, and in AATCC
Test Method 93, each of which documents is also incorporated herein
by reference.
[0031] ASTM document D737-04, which is additionally incorporated
herein by reference, is entitled "Test Method for Air Permeability
of Textile Fabrics". This ASTM document may be considered relevant
to assessing whether particular fabrics and/or clothing items may
be considered highly breathable. Its abstract reads, at least in
part, as follows: [0032] "1.1 This test method covers the
measurement of the air permeability of textile fabrics. [0033] "1.2
This test method applies to most fabrics including woven fabrics,
nonwoven fabrics, air bag fabrics, blankets, napped fabrics,
knitted fabrics, layered fabrics, and pile fabrics. The fabrics may
be untreated, heavily sized, coated, resin-treated, or otherwise
treated."
[0034] AATCC documents 132 and 158, which are likewise incorporated
herein by reference, may be considered relevant to assessing
whether particular fabrics and/or clothing items have good
dimensional stability and/or low shrinkage and/or stretching,
whether subjected to regular laundering or dry cleaning. ASTM
document G 21-80, which is incorporated herein by reference and
bears the title "Determining resistance to Synthetic Polymeric
Materials to Fungi", may be considered relevant in assessing the
resistance of a particular fabric and/or clothing item to insects
and/or fungi.
[0035] It may be an object of the present invention to obviate
and/or mitigate one or more of the above-mentioned disadvantages of
the prior art.
[0036] It may be an object according to one aspect of the present
invention to provide cooler, more breathable flame resistant
single-layer secondary protective clothing which may be
constructed, in whole or in part, using substantially open-textured
flame resistant materials, meshes and/or fabrics.
[0037] It may be an object according to another aspect of the
present invention to provide open-textured materials and/or meshes
and/or clothing made therefrom which may meet current recommended
government and/or industry safety standards for flame resistant
clothing.
[0038] It may be an object according to another aspect of the
present invention to provide open-textured materials and/or meshes
and/or clothing made therefrom which may outperform, under current
recommended government and/or industry safety standards for flame
resistant clothing, when compared to garments constructed from
conventional, solids and/or closed-textured and/or tightly-woven
flame resistant fabrics.
[0039] It may be an object according to another aspect of the
present invention to provide convertible and/or double-layered
flame resistant secondary protective clothing which may be
constructed, in whole or in part, from substantially open-textured
flame resistant materials, meshes and/or fabrics.
[0040] It may be an object according to another aspect of the
present invention to provide open-textured flame resistant
materials and/or meshes and/or convertible and/or double-layered
flame resistant secondary protective clothing made therefrom which
may meet current recommended government and/or industry safety
standards for flame resistant clothing.
[0041] It may be an object according to another aspect of the
present invention to provide open-textured flame resistant
materials and/or meshes and/or convertible and/or double-layered
flame resistant secondary protective clothing made therefrom which
may excel, under current recommended government and/or industry
safety standards for flame resistant clothing, when compared to
garments constructed front a single-layer of conventional, solid,
and/or closed-textured flame resistant fabrics.
[0042] It may be an object according to one aspect of the present
invention to provide safety outerwear having a vent portion that
possesses dimensional stability, low shrinkage and/or stretching,
resistance to degradation by chemicals and/or industrial solvents,
thermal stability, resistance to prolonged heat, a minimized
embrittlement in extreme cold, ultra violet radiation resistance,
and/or resistance to insects and/or fungi.
[0043] It may be an object according to another aspect of the
present invention to provide an article of outer-layer safety
clothing (herein, alternately referred to as "safety clothing" or
"safety outerwear"--outerwear being defined herein to mean an
article of clothing that is either adapted for exposure to outside
environmental conditions and/or adapted and/or otherwise intended
to be worn as an outer-layer of clothing--whether inside or
out-of-doors) which may be relatively comfortable to wear in warm
conditions, and/or which may, possibly at the same time, maintain
protective qualities which may be comparable to those inherent in
trousers and/or other coverings.
SUMMARY OF THE INVENTION
[0044] In accordance with the present invention, there is disclosed
an article of safety, outerwear that includes a main body piece
adapted to receive in encompassing relation at least a portion of
the body of a wearer in use. The main body piece includes a garment
wall that defines an inside wall portion and an outside wall
portion. The inside wall portion is adapted to present a
substantially smooth surface to the body of the wearer in use. The
outside wall portion is adapted for substantially constant exposure
to environmental conditions and to provide the wearer with
protection against abrasion during normal activity selected from
the group consisting of working activity and athletic activity. The
garment wall is formed at least in part from a vent portion, such
that at least a portion of each of the inside wall portion and the
outside wall portion of the garment wall is defined by the vent
portion. The vent portion is constructed solely from at least one
layer of a mesh material. The vent portion is safety-rated with a
flame resistant rating that qualifies the vent portion for flame
resistant use in hazardous environments. The mesh material
operatively has a substantially open texture for high
breathability.
[0045] According to an aspect of one preferred embodiment of the
invention, a substantial entirety of the garment wall may
preferably, but need not necessarily, be formed from the vent
portion.
[0046] According to an aspect of one preferred embodiment of the
invention, the vent portion may preferably, but need not
necessarily, be substantially co-extant with a substantial entirety
of the main body piece.
[0047] According to an aspect of one alternate embodiment of the
invention, the vent portion may preferably, but need not
necessarily, be co-extant with only a portion of the main body
piece.
[0048] According to an aspect of one preferred embodiment of the
invention, the mesh material may preferably, but need not
necessarily, be constructed at least in part from a synthetic flame
resistant material.
[0049] According to a further aspect of a preferred embodiment of
the invention, the synthetic flame resistant material may
preferably, but need not necessarily, comprise a synthetic flame
resistant fiber that may preferably, but need not necessarily, be
characterized by low stiffness and high elongation, so as to
preferably, but not necessarily, provide textile-like
characteristics, and so as to preferably, but not necessarily,
enable processing of the fiber on conventional textile
equipment.
[0050] According to alternate further aspect of a preferred
embodiment of the invention, the synthetic flame resistant material
may preferably, but need not necessarily, comprise one or more
fibers selected from the group consisting of aromatic polyamide
fibers, para-aramid fibers, meta-aramid fibers, polyamide-imide
fibers, polybenzimidazole fibers, celazole fibers, melamine fibers,
oxidized polyacrylonitrile fibers, and modacrylic fibers.
[0051] According to an aspect of another preferred embodiment of
the invention, the mesh material may preferably, but need not
necessarily, be constructed at least in part from a natural
material. The natural material may preferably, but need not
necessarily, be selected from group consisting of plant-based
fibers and silk-based fibers. Selected plant-based fibers may
preferably, but need not necessarily be cellulose and/or cotton
fibers.
[0052] According to a further aspect of a preferred embodiment of
the invention, the natural material may preferably, but need not
necessarily, comprise a material rendered flame resistant by
surface treatment with a flame retardant chemical.
[0053] According to an alternate further aspect of a preferred
embodiment of the invention, the natural material may preferably,
but need not necessarily, comprise a natural fiber rendered flame
resistant by impregnation of a flame retardant chemical into a
substantial core thereof.
[0054] According to an aspect of another preferred embodiment of
the invention, the mesh material may preferably, but need not
necessarily, be selected from the group consisting of flame
resistant perforated fabrics, flame resistant lattice-type fabrics,
and flame resistant open-work fabrics. Selected perforated fabrics
may preferably, but need not necessarily, be conventional mesh
materials. Selected lattice-type fabrics may preferably, but need
not necessarily, be materials having an open-weave structure.
Selected open-work fabrics may preferably, but need not
necessarily, be lace-type fabrics.
[0055] According to an aspect of one preferred embodiment of the
invention, the flame resistant rating may preferably, but need not
necessarily, comprise char length values, afterflame values, and
afterglow values compliant with the vertical flame test under
Method 5903.1 of United States Federal Standard 191A .
[0056] According to an aspect of one preferred embodiment of the
invention, the flame resistant rating may preferably, but need not
necessarily, comprise char, length values, afterflame values, and
afterglow values compliant with the vertical flame test in
accordance with the American Society for Testing and Materials
D-6413 standard.
[0057] According to an aspect of one preferred embodiment of the
invention, the flame resistant rating may preferably, but need not
necessarily, comprise an arc thermal performance value rating
substantially within the range of between about a 0.1 rating and
about a 5.0 rating. The flame resistant rating may preferably, but
need not necessarily, further comprise a hazard/risk category
rating substantially within the range of between about a 0.1 rating
and about a 1.0 rating.
[0058] According to an aspect of another preferred embodiment of
the invention, the flame resistant rating may preferably, but need
not necessarily, comprise an arc thermal performance value rating
substantially greater than about a 5.0 rating. The flame resistant
rating may preferably, but need not necessarily, further comprise a
hazard/risk category rating of substantially greater than about a
1.0 rating.
[0059] According to an aspect of one preferred embodiment of the
invention, the flame resistant rating may preferably, but need not
necessarily, comprise a rating compliant with the National Fire
Protection Association 2112 standard.
[0060] According to an aspect of one preferred embodiment of the
invention, the mesh material may preferably, but need not
necessarily, have an actual weight of substantially about 6.0
ounces per square yard. The flame resistant rating may preferably,
but need not necessarily, comprise a thermal protective performance
rating of substantially greater than about 6.0 calories per square
centimeter. The thermal protective performance rating may
preferably, but need not necessarily, be obtained in accordance
with the American Society for Testing and Materials D-4108
standard.
[0061] According to an aspect of another preferred embodiment of
the invention, the mesh material may preferably, but need not
necessarily, retain a high visibility dye.
[0062] According to an aspect of one preferred embodiment of the
invention, the main body piece may preferably, but need not
necessarily, include a trunks outerwear part and a pair of tubular
leg parts. The trunks outerwear part may preferably, but need not
necessarily, be adapted to receive in encompassing relation the
lower region of the torso of a wearer in use and may preferably,
but need not necessarily, have apertures through which the legs of
the wearer protrude in use. Each of the tubular leg parts may
preferably, but need not necessarily, be adapted to receive
therethrough a respective protruding leg of the wearer in use and
each may preferably, but need not necessarily, extend between a
respective upper end, connected to the trunks outerwear part, and a
respective lower end, disposed adjacent to the ankle of the
respective protruding leg. One vent portion may preferably, but
need not necessarily, be provided in each leg part as a tubular
vent portion that may preferably, but need not necessarily, extend,
with respect to the respective protruding leg received in the each
leg part in use, from about mid leg to about the ankle.
[0063] According to a further aspect of one preferred embodiment of
the invention, the main body piece may preferably, but need not
necessarily, be trouser outerwear.
[0064] According to an aspect of another preferred embodiment of
the invention, the main body piece may preferably, but need not
necessarily, include a trunks outerwear part, a pair of tubular leg
parts, and a bib part. The trunks outerwear part may preferably,
but need not necessarily, be adapted to receive in encompassing
relation the lower region of the torso of a wearer in use and may
preferably, but need not necessarily, have apertures through which
the legs of the wearer protrude in use. Each of the tubular leg
pars may preferably, but need not necessarily, be adapted to
receive therethrough a respective protruding leg of the wearer in
use and each may preferably, but need not necessarily, extend
between a respective upper end, connected to the trunks outerwear
part, and a respective lower end, disposed adjacent to the ankle of
the respective protruding leg. The bib part may preferably, but
need not necessarily, be securely attached to the trunks outerwear
part. The bib part, the trunks outerwear part, and the leg parts
together may preferably, but need not necessarily, form a bib
overall. At least one vent portion may preferably, but need not
necessarily, be provided in the bib overall.
[0065] According to an aspect of one preferred embodiment of the
invention, the main body piece may preferably, but need not
necessarily, include a trunks outerwear part, a pair of tubular leg
parts, and a front-closure jacket part. The trunks outerwear part
may preferably, but need not necessarily, be adapted to receive in
encompassing relation the lower region of the torso of a wearer in
use and may preferably, but need not necessarily, have apertures
through which the legs of the wearer protrude in use. Each of the
tubular leg parts may preferably, but need not necessarily, be
adapted to receive therethrough a respective protruding leg of the
wearer in use, and each may preferably, but need not necessarily,
extend between a respective upper end, connected to the trunks
outerwear part, and a respective lower end, disposed adjacent to
the ankle of the respective protruding leg. The front-closure
jacket part may preferably, but need not necessarily, be securely
attached to the trunks outerwear part. The jacket part, the trunks
outerwear part, and the leg parts may preferably, but need not
necessarily, together form a coverall. At least one vent portion
may preferably, but need not necessarily, be provided in the
coverall.
[0066] According to an aspect of one preferred embodiment of the
invention, the main body piece may preferably, but need not
necessarily, include an upper torso outerwear part and a pair of
tubular arm parts. The upper torso outerwear part may preferably,
but need not necessarily, be adapted to receive in encompassing
relation the upper region of the torso or a wearer in use, and it
may preferably, but need not necessarily, have apertures through
which the arms of the wearer protrude in use. Each of the tubular
arm parts may preferably, but need not necessarily, be adapted to
receive therethrough a respective protruding arm of said wearer in
use, and each may preferably, but need not necessarily, extend
between a respective upper end, connected to the upper torso
outerwear part, and a respective lower end, disposed in a wristward
direction from the respective upper end along the respective
protruding arm. At least one vent portion may preferably, but need
not necessarily, be provided in at least one of the upper torso
outerwear part and the arm parts.
[0067] According to a further aspect of a preferred embodiment of
the invention, the upper torso outerwear part may preferably, but
need not necessarily, be shaped to define a front opening, and the
upper torso outerwear part may preferably, but need not
necessarily, include a front-closure means for securing the front
opening of the upper torso outerwear part in a closed
configuration.
[0068] According to a further aspect of a preferred embodiment of
the invention, the long-sleeved pull-over shirt may preferably, but
need not necessarily, be adapted to be worn as an outer layer of
clothing.
[0069] According to an aspect of another preferred embodiment of
the invention, the article may preferably, but need not
necessarily, also include a covering shell that may preferably, but
need not necessarily, be substantially secured to the main body
piece for covering the vent portion. The covering shell may
preferably, but need not necessarily, be adapted to be turned back
from the vented portion into an opened configuration. The covering
shell may preferably, but need not necessarily, be selectively
securable in the opened configuration by securement means affixed
to the main body piece.
[0070] According to an aspect of another preferred embodiment of
the invention, the article may preferably, but need not
necessarily, also include a covering shell that may preferably, but
need not necessarily, be detachably secured by securement means
affixed to the main body piece for covering the vent portion.
[0071] According to a further aspect of a preferred embodiment of
the invention, the covering shell may preferably, but need not
necessarily, be constructed of a fabric material of a substantially
closed texture.
[0072] According to another aspect of a preferred embodiment of the
invention, the fabric material may preferably, but need
necessarily, be formed at least in part from a high temperature
flame resistant petrochemically-based manufactured fiber.
Alternately, the fabric material may preferably, but need not
necessarily, be formed at least in part from a natural fiber that
may preferably, but need not necessarily, be rendered flame
resistant by a process selected from the group consisting of
surface treatment with a flame retardant chemical, and impregnation
of a flame retardant chemical into a substantial core thereof.
[0073] According to an aspect of another preferred embodiment of
the invention, the main body piece may preferably, but need not
necessarily, include a pocket means for temporarily storing items
during a normal activity selected from the group consisting of
workplace activities and athletic activities. The pocket means may
preferably, but need not necessarily, comprise at least one pocket
that may preferably, but need not necessarily, be sized to receive
and store a covering shell which may preferably, but need not
necessarily, be detachably securable to the main body piece for
covering the vent portion.
[0074] According to an aspect of another preferred embodiment of
the invention, the article may preferably, but need not
necessarily, also include a pair of pads attached to the main body
piece to preferably, but not necessarily, cover a first pair of
body parts of the wearer in use that may preferably, but need not
necessarily, be selected from a pair of knees and a pair of hips of
the wearer.
[0075] According to a further aspect of a preferred embodiment of
the invention, the pads may preferably, but need not necessarily,
be removably attached to the main body piece.
[0076] Preferably, the mesh material may be adapted to provide the
wearer with protection against burn and/or flame hazards, and/or
electrical arc hazards.
[0077] In accordance with the present invention, there is disclosed
safety clothing for use in environments requiring protective
clothing, such as in industrial settings and in athletic pursuits,
including rollerblading. According to this aspect of the invention,
open-textured materials and open-textured fabrics may be utilized
in secondary flame resistant garments that satisfy various
recommended safety standards for workers exposed to risks of flash
fires and/or electrical arc hazards.
[0078] It may thus be an object of this invention to obviate and/or
mitigate one or more of the above-mentioned disadvantages of the
prior art.
[0079] Other advantages, features and/or characteristics of the
present invention, as well potentially as methods of operation
and/or functions of the related elements of the structures and/or
the combination of parts and/or economies of manufacture, may
become more apparent upon consideration, of the following detailed
description and/or the appended claims with reference to the
accompanying drawings, the latter of which are be briefly described
hereinafter.
BRIEF DESCRIPTION OF THE DRAWINGS
[0080] The novel features which are believed to be characteristic
of the safety outerwear with fire resistant mesh according to the
present invention, as to its structure, organization, use, and/or
method of operation, together possibly with further objectives
and/or advantages thereof, will be better understood from the
following drawings in which a presently preferred embodiment of the
invention may now be illustrated by way of example. It is expressly
understood, however, that drawings are for the purpose of
illustration and/or description only, and are not intended as a
definition of the limits of the invention. In the accompanying
drawings:
[0081] FIG. 1 is a front elevational view of an article of safety
clothing according to a preferred embodiment of the present
invention;
[0082] FIG. 2 is a partially exploded view of the article of safety
clothing shown in FIG. 1;
[0083] FIG. 3 is a side elevational view or structure of FIG.
2;
[0084] FIG. 4 is an exploded view of the unexploded portion of the
article shown in FIG. 2;
[0085] FIG. 5 is a front elevational view of an article of safety
clothing according to a first alternate embodiment of the
invention;
[0086] FIG. 6 is a view of the article of safety clothing shown in
FIG. 5, shown in a first partially exploded configuration;
[0087] FIG. 7 is a view of the article of safety clothing shown in
FIG. 6, shown in a second partially exploded configuration;
[0088] FIG. 8 is a view of the article of safety clothing shown in
FIG. 7, shown in a fully exploded configuration;
[0089] FIG. 9 is a front elevational view of an article of safety
clothing according to a second alternate embodiment of the
invention;
[0090] FIG. 10 shows a recommended configuration for single-layer
fabric TPP testing performed according to the ASTM D-4108/NPA 1971.
standard;
[0091] FIG. 11 shows simulated flash-fire testing using a mannequin
system at before, during, and after exposure to a simulated
flash-fire;
[0092] FIG. 12 shows a tabulated summary of the hazard risk
categories, and some sample common tasks, types of clothing, and
typical ATPV values for single and multi-layer applications;
[0093] FIG. 13 shows a swatch card and close up of NOMEX.RTM. Type
462 test mesh;
[0094] FIG. 14 shows a graphic representation of the thickening of
NOMEX III fabric when exposed to heat and flame, in accordance with
ASTM-4108 TPP testing, with the shown thicknesses representing the
nominal overall thickness of the fiber;
[0095] FIG. 15 is a photographic image depicting the carbonization
and thickening of NOMEX.RTM. III fabric when exposed to heat and
flame, in accordance with ASTM D-4108 TPP testing, with the shown
thicknesses representing the nominal overall thickness of the
fabric;
[0096] FIG. 16 shows a graphic representation of various sample
garment testing results according to the NFPA 2112 standard with a
three second exposure;
[0097] FIG. 17 shows various sensor locations on the front and rear
sides of the DuPont THERMO-MAN.RTM. mannequin;
[0098] FIG. 18 shows a pair of convertible ventilated work pants
according to the invention, with a right leg cover removed and with
a left leg cover partially open;
[0099] FIG. 19 shows the images of the lower body burns sustained
in tests 1 through 4, wherein the color brown indicates second
degree burns and the color red indicates third degree burns;
and
[0100] FIG. 20 shows a tabulated summary of the mannequin test
results in the four mannequin tests of FIG. 19
DETAILED DESCRIPTION OF A PREFERRED EMBODIMENT
[0101] Referring now to FIG. 5 of the drawings there is shown an
article of safety clothing according to a first alternate
embodiment of the present invention and designated with general
reference numeral 20.
[0102] As best indicated in FIG. 7, the article 20 comprises a main
body piece 22. In the preferred embodiment illustrated, the main
body piece 22 takes the form of a pair of trousers adapted to be
worn as an outer layer of clothing. The trousers or main body piece
22 include a trunks part 24 which is also adapted to be worn as an
outer layer of clothing, and a pair of tubular leg parts 28
(hereinafter, alternately referred to as pant leg parts). The
trunks part 24 is adapted to receive in encompassing relation the
lower region of the torso of a wearer in use and has apertures,
defined in dotted outline in FIG. 7 and designated with general
reference numerals 26, trough which the legs of said wearer
protrude in use. The tubular pant leg parts 28 are each adapted to
receive therethrough a respective protruding leg of said wearer in
use and extend between a respective upper end 30, connected to said
trunks part 24, and a respective lower end 32, disposed adjacent
the ankle of said respective protruding leg in use.
[0103] In the preferred embodiment illustrated, the trunks part 24
is substantially opaque, so as to conceal the pelvic region of the
wearer in use, and is constructed of relatively sturdy and washable
material of substantially closed texture.
[0104] Each pant leg part 28 of the preferred embodiment includes a
tubular vent portion 34 extending, with respect to the respective
leg disposed within said each leg part 28 in use, from about
mid-leg to about the ankle.
[0105] The vent portion 34 is constructed substantially from mesh.
The mesh preferably has a substantially open texture for high
breathability, and presents a substantially smooth surface to the
legs of the wearer in use. The mesh is adapted to provide the
wearer with protection against abrasion in a normal activity
selected from the group consisting of working and athletic
activities. In the preferred embodiment illustrated, the mesh is a
mesh material that is adapted for high visibility, for safety.
[0106] In the first alternate embodiment illustrated, a reinforced
cuff 36 is sewn onto the mesh at the lower end 32 of the leg part
28. The provision of such reinforced cuff 36 avoids undue wear,
which might otherwise occur if the mesh extended fully through to
the lower end 32.
[0107] As best seen in FIG. 6, other features of the first
alternate embodiment include a pair of first pads 38 which are
removably attached to the main body piece 22 to cover respective
knees of the wearer in use, as well as a pair of second pads 40
which are removably attached to the main body piece 22 to cover the
respective hips of the wearer in use. As best indicated in FIG. 7,
such removable attachment is effected, in the preferred embodiment,
by hook 42 and loop 44 fasteners, of the type sold by Velcro Inc.
under the trade-mark VELCRO, secured to the pads 38, 40 and the
main body piece 22, respectively. The first pads 38 and the second
pads 40 are shown attached to the main body piece 22 in FIG. 6, and
detached therefrom in FIG. 7.
[0108] As a further feature illustrated in FIG. 5, a pair of
tubular leg shells 46 are preferably provided, and detachably
secured to the main body piece 22 for covering the pant leg parts
28 and, when attached, the first pads 38. Shells 46 are constructed
of relatively durable, weatherproof, washable and fire-resistant
material of substantially closed texture, so as to maximize
protection from, inter alia, the elements and workplace hazards,
when attached.
[0109] Such detachable securement of the shells 46 is effected, in
the preferred embodiment illustrated, by a plurality of
conventional snaps. Each snap comprises a male snap 50 and a female
snap 52. The female snaps 52, as illustrated in FIG. 7, are fixedly
secured to band portions 35 which extend about the pant leg parts
28 and about the reinforced cuffs 36. The male snaps 50, as
indicated in FIG. 6, are fixedly secured about the inner periphery
of tubular fillet portions 37 which are disposed at opposite ends
54 of the shells 46.
[0110] In use, the article of safety clothing 20 can be worn in the
manner of conventional trousers. In, for example, cold weather, the
shells 46 may be slipped over the leg parts 28, and secured to the
trunks part 24 by snaps 50, 52. In hot weather, on the other hand,
the process may be reversed, and the shells 46 may be rolled up and
conveniently stored in, for example, a lunch box, thereby to expose
the mesh and provide comfort to the wearer, while at the same time
providing protection against abrasion and burn injuries. Depending
upon the type of activity in which the wearer is to be engaged, the
first pads 38 and the second pads 40 may be secured to the main
body piece 22, or removed from the main body piece 22 and
stored.
[0111] In the first alternate embodiment illustrated, the
reinforced cuffs 36, fillet portions 37 and band portions 35 are
constructed of a reflective fabric, so as to render the wearer more
visible to, inter alia, motorized vehicles.
[0112] A preferred embodiment of the invention is illustrated in
FIGS. 1 through 4. The article of safety clothing of this
embodiment, designated with general reference numeral 20', differs
from the first alternate embodiment in that a zippered-front jacket
part 70 is provided and securely attached to the trunks part 24,
with the jacket part 70 and the main body piece 22 together forming
a coverall 72.
[0113] As well, in contrast to the situation of the preferred
embodiment wherein the pant leg parts 28 were tailored in the
manner of a conventional pair of trousers, the tubular vent portion
34 of each pant leg part 28 in the first alternative embodiment
tapers towards the lower end 32, and the leg shells 46 are
similarly tapered. Among other things this feature permits the leg
shells 46 to be interchangeable, for use on other leg. In most
other material respects, the structure of the preferred embodiment
is identical to that of the first alternate embodiment.
[0114] A second alternate embodiment of the invention is
illustrated in FIG. 9 and designated with general reference numeral
20''. In contrast to the first alternative embodiment wherein a
jacket part 70 was provided, a bib part 74 is provided in the
second alternative embodiment. The bib part 74 is securely attached
to the trunks part 24, with the bib part 74 and the main body piece
22 together forming a bib overall 76. In all other material
respects, the structure of the second alternate embodiment is
substantially identical to that of the preferred embodiment, and
accordingly, is not described. In substantially greater detail
herein.
[0115] Various other modifications may be used in the design and
manufacture of the article of safety clothing according to the
present invention without departing from the spirit and scope of
the invention.
[0116] For example, whereas the vent portions of the preferred
embodiment extend from about the knee to about the ankle, such that
the non-mesh portions of the pant leg parts and the trunks part
form knee breeches, it will be evident that the vent portions could
be smaller or larger, to suit the style of the wearer.
[0117] Further, whereas the first pads and the second pads of the
preferred embodiment are removably attached by hook and loop
fasteners, it will be evident that other means for such removable
attachment, such as, for example, zippers, could be utilized.
[0118] Moreover, the first pads and the second pads could be
rigidly affixed, by stitching, or omitted altogether.
[0119] Yet further, whereas the shells of the preferred embodiment
are secured by snaps, it will be evident that securement could be
effected through other conventional means, such as zippers, buttons
or hook and loop fasteners.
[0120] As well, whereas in the preferred embodiment illustrated,
the reinforced cuffs, fillet portions and band portions are
constructed of a reflective fabric, it should be understood that
alternatively, reflective material could be secured to the main
body piece, for example, in a vertical line along each outer
seam.
[0121] Moreover, while reinforced cuffs are provided in the
preferred embodiment, it should be understood that cuffs are not
essential. For example, the ends of the pant leg parts could be
provided with drawstring closures, elastic banding or a flap-type
closure, with hook and loop fasteners, in circumstances wherein it
was desired to ensure a snug fit around, for example, the safety
boots of a wearer. Stirrups could also be provided, so as to ensure
that the pant leg parts did not inadvertently ride up on the legs
of the wearer, and expose same to possible injury.
[0122] It is additionally noted, with regard to each of the
embodiments and garments described herein, that the vented mesh
portion may extend substantially over the entire garment so as to
be substantially co-extensive therewith, or preferably it may only
extend over a portion thereof. The garment preferably includes
covering shells that are adapted to be removably fastened over the
vented mesh portions, or alternately, it may not be provided with
any covering shells whatsoever. Any such covering shells might
include zippered fasteners and might also, or instead, open and
roll, turn, and/or fold back from the vented mesh portions to be
subsequently snapped in place in the opened configuration.
[0123] Further still, it should be appreciated that while pants,
coveralls, overalls, long sleeved shirts and jackets are described
herein, the invention may comprise any form, shape or configuration
of garment provided with a flame resistant vented portion that is
constructed of a breathable and substantially open-textured flame
resistant material, whether the material is inherently flame
resistant at the fiber level, or whether it is treated so as to
render it flame resistant.
[0124] Accordingly, it should be understood that the present
invention is limited only by the accompanying claims and the claims
of any regular patent application claiming priority therefrom, as
purposely construed.
[0125] Provided hereinbelow is an additional detailed description
of the preferred embodiment of the invention, together with tables
which are provided for the purpose of illustration and description
only, and are not intended as a definition of the limits of the
invention, but rather of some of its flame resistant advantages in
relation to, among other things, momentary electric arcs, flash
fires, and/or molten metal splash exposure.
[0126] In the prior art, flame-resistant primary and secondary
garments may have been constructed using fabrics that were woven
either from man-made fibers, from natural fibers, and/or from a
combination of the two.
[0127] The predominant man-made flame resistant (hereinafter FR)
material that has been in use in the prior art may have been a
product called NOMEX.RTM. material NOMEX.RTM. is an E. I. DuPont
registered trademark for its family of aromatic polyamide (aramid)
fibers. Aramid fibers are inherently flame-resistant, i.e., the
flame resistance is an inherent property of the polymer chemistry,
meaning that the fibers themselves may not be subject to burning in
air. NOMEX.RTM. material may not melt and/or drip, and/or it may
merely char when exposed to high temperatures for prolonged
periods. It may also provide a high degree of heat resistance
and/or it may be extremely resistant to chemical attack. These
properties may not diminish during the life of the fiber, and the
fiber's low stiffness and high elongation may give textile-like
characteristics which allow for it to be processed on conventional
textile equipment. DuPont's KEVLAR.RTM. material may be a much
stronger fiber from the same aramid family, and though it may be
best known for its use in bulletproof vests it is also commonly
used in flame resistant garments.
[0128] In the prior art, traditional natural fibers such as cotton
may also have be rendered flame resistant after being
surface-treated with a flame retardant chemical, and/or by infusing
such chemicals into the very core of the fibers. Industry leaders
in this flame retardant treated (hereinafter, FRT) area of
technology may include Chicago, Ill. based Westex, and their line
of INDURA.RTM. and INDURA.RTM. Ultra Soft.RTM. chemically treated
fabrics. In INDURA.RTM. engineered fabrics, the flame retardant
chemical which may have been impregnated into the core of a cotton
fiber may act as a catalyst that may promote the charring of the
fabric when exposed to flames. Though not essential to the working
of the present invention, this accelerated charring may be
generally believed to prohibit the support of continued combustion
by starving the flame of its fuel source. Contrary to popular
belief, however, the flame retardant chemical may act in its solid
form by creating an exothermic reaction to produce this char, and
the mechanism of action may not be based on a gaseous process of
extinguishing or "snuffing out" the flame.
[0129] In the prior art, fabrics for thermal protective apparel may
be evaluated for various properties using a broad range of test
methods based on industry standards. In particular, there may be
four laboratory test procedures which may be commonly used to
demonstrate the unique flame resistant characteristics of any
particular fabric. These may include the Vertical Flame Test, the
Thermal Protective Performance Test or (TPP) Test, the Instrumented
Mannequin Tests for Flash Fires, and the Instrumented Mannequin and
Panel Tests for electric arc exposure. These tests may be used as
benchmarks to achieve NFPA 2112 and NFPA 70E certification for
potential new FR or FRT fabrics. Industry certification aids in the
commercialization of any new FR or FRT fabrics because most of the
potential end users require garments that are made using certified
or "rated" (herein, alternately also referred to as "safety-rated")
fabrics. To achieve certification, independent testing as per these
four tests may be required. Once a fabric has been "rated", or in
other words, satisfies the minimum requirements as per these tests,
it may be used in any configuration in garment construction as the
fabric may have been labeled with a protective "rating" specific to
its construction, fiber content, and/or weight. Armed with this
knowledge, purchasers may then make informed clothing-buying
decisions, possibly by simply selecting from garments constructed
from safety-rated fabrics that may satisfy the level of protection
that their employees may require in their particular workplace.
This fabric rating system may also eliminate the need for garment
manufacturers to test every individual existing an/or new garment
design, as the continuing costs of the independent testing might
otherwise quickly become prohibitive.
[0130] The Vertical Flame Test (Federal Standard 191A, Method
5903.1 and/or ASTM D-6413 standard) may measure the relative
flammability of a fabric specimen suspended vertically in a three
sided frame. A methane burner may provide a small igniting flame
which may then be allowed to burn on the bottom edge of the fabric
for 12 seconds. The char length, afterflame (the amount of time
flames may continue to be observed on the fabric surface after the
burner is turned off or removed), afterglow (the amount of time the
fabric may continues to glow after any afterflame stops) and/or
other relevant observations may be recorded. This test may
typically be a qualitative pass/fail indicator of fabric
flammability and may be importance for protective apparel, because
a fabric that may ignite and/or burn may contribute to burn injury
rather than reducing it. However, the vertical flame test may not
measure thermal protective performance and, consequently, it alone
may not be an effective discriminator among flame resistant
materials. Table 1 may show typical results of vertical
flammability tests which may have been performed on solid fabrics
of NOMEX.RTM. IIIA, 65%/35% polyester/cotton and 100% cotton.
TABLE-US-00001 TABLE 1 Weight Char length Afterflame Fabric
(oz/yd2) (in) (sec) NOMEX .RTM. IIIA 14.5 3.3 0 NOMEX .RTM. IIIA
6.1 3.1 0 65%/35% Polyester/Cotton 8.6 12.0 48.5 100% Cotton 9.0
12.0 36.0
[0131] The thermal protective properties of fabrics and/or fabric
systems may be demonstrated through the use of the Thermal
Protective Performance (TPP) Test, as may be described in National
Fire Protection Association Standard NFPA 1971 and American Society
for Testing and Materials (ASTM) D-4018. This test may also be used
to assess the integrity of fabrics under thermal load--a
potentially important consideration in protective apparel. The TPP
test may not be applicable to non-FR fabrics.
[0132] The equipment which may be required to perform the TPP test
may be seen in FIG. 10. As normally practiced, a combined
convective/radiant heat source with a heat flux of 2 calories per
square centimeter per second may be impinged upon the outer surface
of a 4-inch by 4-inch square area of the fabric system, and the
time required to reach the equivalent of a second-degree burn at
the calorimeter on the other side of the fabric system may be
recorded. This time (in seconds), multiplied by the heat flux of
the exposure, may give the TPP rating of the system. The higher the
TPP value, the more protection a fabric or system may provide to
the wearer.
[0133] As mentioned above, a recommended configuration for
single-layer fabric TPP testing performed according to the ASTM
D-4108/NFPA 1971 standard may be seen in FIG. 10. Such testing may
typically includes a calorimeter, at least one 1/4 inch spacer, the
test fabric, a movable shutter, a gas burner, and/or radiant tubes.
ASTM D-4108 may specify two methods for TPP testing. When testing
single-layer fabrics, a 1/4-inch spacer may be placed between the
fabric sample and the heat sensor, possibly to simulate the normal
fit of protective clothing and/or to allow the fabric to reach as
high a temperature as may occur in an actual flame exposure. TPP
results for single-layer standard woven fabrics of NOMEX.RTM. IIIA
are listed in Table 2, where it may be seen that, for a specific
material type, the TPP value may increase with increasing fabric
weight. When testing multilayer fabrics and/or systems, such as
firefighters' turnout coats, the ASTM standard may specify that the
sample and/or heat sensor be in contact with the innermost fabric
layer of the system and/or that no spacer is to be used for
multilayer fabric samples. It may be important to note at this time
that, when multiple layers of FR fabrics are evaluated using these
test methods, the test results may be higher than the additive TPP
rating for each layer. This result may be explained by enhanced
insulation resulting from a combination of heat transfer through
the different layers and/or by entrapped air between the layers.
TABLE-US-00002 TABLE 2 Sample TPP Ratings of Single Layer Fabrics
per ASTM D-4108 with Combined Convective and Radiant Heat Source
(recommended Configuration for Single-Layer Fabrics) * Actual
Weight TPP Fabric (oz/yd.sup.2) (cal/cm.sup.3) NOMEX .RTM. IIIA 4.5
11.8 NOMEX .RTM. IIIA 6.0 13.3 NOMEX .RTM. IIIA 7.5 15.3 65%
Polyester/35% Cotton N/A - Ignites 100% Cotton N/A - Ignites 2.0
cal/cm.sup.3-sec heat flux. Fabrics were home laundered one time
prior to testing. N/A Not Applicable.
[0134] Along with the Vertical Flame Test and the TPP Test, actual
garments constructed from FR and FRT materials may be burn tested
on instrumented mannequins in accordance with ASTM F1930, the
"Flash Fire Mannequin Test for Predicted Body Burn Injury".
DuPont's mannequin system, the THERMO-MAN.RTM. system, is an
instrumented laboratory mannequin that may utilize skin model
software to determine the predicted burn injury in a carefully
controlled, reproducible laboratory flash fire. It may be generally
believed, though not essential to workings of the present
invention, that the idea is to simulate actual conditions that
workers may be exposed to in, for example, a petrochemical refinery
flash-fire. A simulated flash-fire testing using the
THERMO-MAN.RTM. system may be seen in FIG. 11 at three different
stages, namely, before, during, and after exposure. Data obtained
from one hundred and twenty-four (124) heat sensors distributed
over the mannequin body may be used to measure the heat transmitted
from the fire through the test garment to the surface of the
mannequin. A sophisticated computer program may then calculate the
predicted percentage of second and/or third-degree burns and/or may
indicate the burn injury locations for the selected simulated flash
fire exposure conditions. Under guidelines from NFPA 2112 and ASTM
1930, the THERMO-MAN.RTM. mannequin may be dressed in a T-shirt and
briefs of 100% cotton as well as the garment to be tested, and may
then be subjected to a propane gas flash fire of a minimum of 3
seconds in duration, with a heat flux of 2.0 cal/cm.sup.2/sec.
[0135] Under these conditions, garments made form standard 6.1
oz/yd.sup.2 solid woven/closed textured fabrics of inherently
flame-resistant NOMEX.RTM. IIIA material may generally limit the
predicted second-degree and/or third-degree body burns to
substantially less than or equal to about 35%. In a similar test,
garments made from untreated 100% cotton (6.5 oz/yd.sup.2 shirt+8.5
oz/yd.sup.2 pants) and/or from untreated 65%/35% polyester/cotton
(7.5 oz/yd.sup.2 coverall) may exhibit predicted second and/or
third-degree burns in the substantial range of from about 75% to
about 90% of the body. Data compiled by the American Burn
Association may indicate that a body burn level in the substantial
order of about 90% of the body may translate into substantially
less than or equal to about 30% chance of survival for the persons
in the 20s and 30s age groups, and/or substantially less than or
equal to about 15% chance of survival for persons in the 40s and
50s age groups. In contrast, the chance of survival corresponding
to a burn injury level in the substantial order of about 40% of the
body may be greater than or equal to about 80% for all age groups.
It may be important to note here that, in order to achieve ratings
for fabrics to be used for FR garments as per this test, NFPA 2112
may set the test failure at above about 50% Total Body Burn.
[0136] When compared to a flash fire as described earlier, the
intense energy and/or very short duration of an electric arc flash
may represent a very unique exposure. While it may be generally
well-recognized that exposure to electric arcs can cause electric
shock injury as the arc current passes through and/or along the
surface of the human body, it may not be as well-recognized that
the intense radiant and/or convective energy from an electric arc
and/or the subsequent ignition of work clothing may cause serious
burn injury, possibly even if there may be no contact with the arc.
When an electric current passes through air between ungrounded
conductors and grounded conductors, the temperatures may, even if
only substantially briefly, reach substantially in the order of
about 35,000.degree. F. In fact, non-contact burn injuries may make
up the majority of the injuries resulting from electric arc
accidents.
[0137] Untreated cotton clothing may sometimes have been worn by
electric utility workers in the prior art who may not be exposed to
electric arc hazards, and/or where their potential arc exposure may
be so minimal that there may be insufficient incident energy
available to ignite untreated cotton clothing. However, everyday
work clothes made from regular cotton and/or poly/cotton fabrics,
regardless of weight, may be readily ignited at some exposure level
and/or may continue to burn, which may add to the extend of injury
which might be sustained from the arc alone. It was perhaps for
these reasons that ASTM F1506 ("Standard Performance Specification
for Textile Materials or Wearing Apparel for Use by Electrical
Workers Exposed to Momentary Arc and Related Thermal Hazards") may
have been developed to give minimum performance specifications for
protective clothing. The major requirement of this specification
may be that the fabric is flame resistant, as may be determined in
accordance with a standard vertical flame test.
[0138] The potentially heightened awareness in recent years of arc
flash hazards may have prompted changes to the National Fire
Protection Association (NFPA) 70E standard. The latest edition of
the NFPA 70E standard ("Standard for Electrical Safety in the
Workplace") was published in 2004. The standard may states as
follows: "employees shall wear FR clothing wherever there is a
possible exposure to an electrical arc flash." It may include a
chart which, although it may not be reproduced herein, lists common
tasks an electrical and/or maintenance worker may perform and it
may assign a respective hazard/risk category (HRC) that is to be
associated with each task.
[0139] ASTM may have developed a test method to assist in
determining and/or comparing the protective capacity of various
flame resistant fabrics against electric arc flashes, namely, ASTM
F1959 being a "Standard Test Method for determining the Arc Thermal
Performance Value (ATPV) of Materials for Clothing". Using this
test, the protective performance of various work wear fabrics
and/or systems in an electric arc exposure may be determined using
instrumented panels and/or mannequins. The mannequins and/or panels
may be equipped with copper calorimeters to measure temperature
rise, in a manner that may be generally similar to the TPP test
method described earlier. When this test method is run, the arc
discharge may cause a dramatic temperature rise in the receiving
sensors over a short period of time (typically less than 1 second).
The temperature rise at each calorimeter may be compared with
available second-degree burn criteria to determine whether a burn
may be predicted under the test conditions. In addition,
observations may be made regarding fabric ignition, melting,
dripping, shrinkage, brittleness, and/or weakness, possibly in
addition to observations as to whether the fabric "breaks open" and
may consequently be thought, according to the prior art, to no
longer provide a barrier against heat and/or flame. Using this
method, the data for ATPV for fabrics may be obtained, the fabrics
may be assigned an ATPV value and/or rating, and the resulting
clothing which is made therefrom may then be associated with the
proper HRC guidelines, as described earlier. At this time, it may
again be relevant to note that, as was the case with the TPP
ratings of fabrics, FR and/or FRT fabrics may also show a higher
combined ATPV rating when used in layered applications than the sum
of their individual ratings alone. Again, this result may be
explained by enhanced insulation resulting from a combination of
heat transfer through the different layers and/or entrapped air
between the layers.
[0140] A tabulated summary of the hazard risk categories, and some
sample common tasks, types of clothing, and typical ATPV values for
single and/or multilayer applications may be seen in FIG. 12.
[0141] It is extremely important to stress that, while regular,
closed-textured, and/or solid-woven FR and/or FRT fabrics meeting
minimum recommended NFPA 2112 and/or NFPA 70E standards for
flame-resistant secondary garment construction may have been
readily available in the prior art, the prior art does not disclose
the use of a single-layer of open-textured FR and/or FRT materials
and/or fabrics that satisfy these same guidelines, nor is there any
prior art which teaches the added protective benefits associated
with the use of open-textured materials in flame resistant
clothing. Though not essential to the working and/or utility of the
present invention, it may be generally believed, perhaps because
one of the main end-user complaints regarding flame resistant work
wear may pertain to heat prostration issues arising from a lack of
breathability of closed-textured fabrics, that the use of FR and/or
FRT open-textured meshes, perforated fabrics, lattice-type fabrics,
and/or open-work fabrics may provide extremely breathable FR and/or
FRT garments which may help to alleviate one or more of the
aforementioned problems.
[0142] Recently, various testing of the article of safety outerwear
20 according to the present invention was carried out using a vent
portion formed from an open-textured mesh. The test open-textured
mesh was constructed from a NOMEX.RTM. Type 462 athletic type mesh,
in an attempt to determine its suitability for use in single layer
flame-resistant secondary garments. In particular, the tests were
conducted to confirm that open-textured fabrics might be rated
according to the aforementioned standards, and so as to prove their
appropriate use in any configuration, whether provided in single
and/or multiple layers, and whether provided with or without other
tightly-woven flame resistant fabrics, in the construction of
flame-resistant clothing according to the present invention. It may
be worthwhile to note that, in the prior art, NOMEX.RTM. meshes may
have been generally used in high temperature filtration, airline
interior and/or military materials applications, but there is no
prior art to suggest their use in externally exposed, and/or in
safety-rated single-layer, clothing applications.
[0143] The mesh that was tested according to the invention was a
6.0 oz. NOMEX.RTM. Type 462 material that was obtained from
Tek-Knit Industries of Montreal Quebec, in Canada. As discussed
more generally hereinabove, Type 462 staple NOMEX.RTM. fibers may
be a blend of NOMEX.RTM. and/or KEVLAR.RTM. brand fibers and/or
P-140--a static dissipative carbon fiber. In the prior art, when
the staple fibers may have been converted to closed-textured woven
fabrics for use in thermal protective apparel, it may have been
widely known commercially as NOMEX.RTM. IIIA material. Each such
closed-textured woven fabric may have been rated according to
fabric weight with its corresponding TPP and/or ATPV vales. A sales
swatch card (from the Montreal mill), and a close up of a
representative sample of the NOMEX.RTM. Type 462 mesh used in the
tests performed according to the invention may be seen in FIG. 3.
The close up which may be seen in FIG. 13 may also demonstrate the
open-texture of the mesh. Although clearly marked according to
fabric weight and fiber type, the swatch card attached to the mesh
label makes no mention of NOMEX.RTM. IIIA materials, nor does it
provide TPP and/or ATPV values for the mesh--all of which are
common practice when marking fabrics thought to be suitable for FR
clothing. The similarly complete lack of both a TPP rating and/or
an ATPV rating on the tested FR mesh may have been, in part, a
factor motivating the recent tests performed on the mesh according
to the invention
[0144] When looking at the texture of the flame-resistance mesh in
FIG. 13, the ratio of air holes and/or "open-textured" areas
compared to fiber and/or "closed-textured" area may be
substantially in the approximate order of about 40% of the total
surface area. It may be important to note, at this time, that a
person having ordinary skill in the art would, in view of the
positive test results obtained thus far, have a reasonable
expectation that the test results that were obtained using this
mesh (which are discussed elsewhere herein) would be substantially
equivalent to those test results which might reasonably be
predicted and may yet be obtained using other types of similarly
weighted open-textured FR and/or FRT fabrics and/or materials
(e.g., lace-work, latticed, and/or perforated materials, among
others), provided that the aforementioned ratio of air holes to
fiber (holes:fiber) remains substantially the same.
[0145] Preliminary Vertical Flame and TPP tests carried out on
swatches of mesh material, corresponding in all substantial
respects to that which is represented in FIG. 13, have indicated
that such mesh material, contrary to what a person having ordinary
skill in the art may ha a priori expected on the basis of the prior
art, satisfies current fabric guidelines according to NFPA and ASTM
standards for use in single-layer flame resistant secondary
garments. Vertical Flame test have shown the mesh to have
acceptable ratings for char length, afterflame and afterglow. TPP
tests have demonstrated that, even with its substantially open
texture, the tested mesh on its own passes minimum guidelines for
thermal protective performance when used as a single layer. Though
not essential to the working and/or utility of the present
invention, it is anticipated that awaited results from ATPV testing
which may have been recently performed on the mesh may yield
comparable results.
[0146] Though not essential to the working and/or utility of the
present invention, in hindsight, the satisfactory TPP results
achieved by this particular mesh texture may also be partly
explained by some of the built-in properties of the NOMEX.RTM.
fibers themselves. Though not essential to the working and/or
utility of the present invention, when exposed to intense heat, the
NOMEX.RTM. fibers may be generally thought to carbonize and become
thicker, forming a protective barrier between the heat source and
the sensors. Thus, in hindsight, the NOMEX.RTM. fiber itself may
help to increase the overall TPP rating in three ways: [0147] i.
The fiber itself may absorb heat energy during the carbonization
process. [0148] ii. The fiber may swell and/or help to seal
openings in the mesh, possibly decreasing air movement and/or the
associated convective heat transfer. A graphic representation of
the thickening of NOMEX..RTM. III closed-textured fabrics, when
exposed to heat and flame, may be seen in FIG. 14. Though not
essential to the working and/or utility of the present invention,
FIG. 14 may accurately depict, in accordance with ASTM-4108 TPP
testing, shown thicknesses representing the nominal overall
thickness of the fiber. [0149] iii. One or both of the fiber and/or
the fabric may thicken, possibly increasing the insulative barrier
and/or reducing conductive heat transfer. The carbonization and/or
thickening of NOMEX.RTM. III closed-textured fabric, when exposed
to heat and flame, may be seen in FIG. 15. Though not essential to
the working and/or utility of the present invention, FIG. 15 may
accurately depict in accordance with ASTM D-4108 TPP testing, shown
thicknesses representing the nominal overall thickness of the
fabric.
[0150] While no other FR and/or FRT meshes may have been existence
in the prior art, a person having ordinary skill in the art would,
in view of the positive test results obtained thus far, have a
reasonable expectation that other fabrics, fibers, and/or materials
that may undergo a thickening and/or a carbonization process, when
exposed to intense heat and/or flame (such as, for example,
Westex's INDURA.RTM. and INDURA.RTM. Ultra Soft.RTM. chemically
treated cotton fabrics), would produce comparable results under
similar conditions. As well, by increasing and/or decreasing the
aforementioned holes:fiber ratio (i.e., aperture size) in the mesh
and/or in other perforated, lacework, and/or latticed materials, a
person having ordinary skill in the art would, in view of the
positive test results obtained thus far, have a reasonable
expectation that various acceptable TPP and/or ATPV test results
are yet to be documented according to the NFPA 2112 and/or NFPA 70E
standards. Moreover, a person having ordinary skill in the art
would, in view of the positive test results obtained thus far, have
a reasonable expectation that, according to the invention, such
alternate textures and/or aperture sizes may be adjusted to suit
the minimum thermal protective needs of many different end-users,
while still affording the maximum ventilation characteristics.
[0151] While, as aforesaid, the Vertical Flame and/or TPP and/or
ATPV results on the aforementioned mesh may have been very
positive, the thermal protective properties that the mesh exhibited
when burn tested using the instrumented Mannequin Test for Flash
Fires proved to be even more dramatic.
[0152] NFPA 2113 and Canadian General Standards Board (GCSB) 155.20
define a flash fire as follows: "A rapidly moving flame front which
can be combustion explosion. Flash fire may occur in an environment
where fuel and air become mixed in adequate concentrations to
combust. Flash fire has a heat flux of approximately 84 kW/m.sup.2
for relatively short periods of time, typically less than 3
seconds."
[0153] As a result, 3 seconds of flash fire exposure may have been
established as the NFPA 2112 timeframe for analysis of the
performance of secondary protective clothing and/or fabrics during
the mannequin test. Often, exposure times above three seconds may
be used to more completely profile fabric protective performance
for use in secondary garments. That said, when the risk of exposure
is greater than 3 seconds, layered secondary and/or primary
garments may be highly recommended. As well, although three seconds
may be used, possibly in conjunction with the 50% Total Body Burn
pass/fail threshold, to determine a fabric's potential suitability
for use in protective clothing, it may be widely accepted that the
latent heat retained in the fabric of the garments and/or in the
air trapped inside continues to contribute to additional 2.sup.nd
and/or 3.sup.rd degree body burns, possibly long after the 3 second
exposure has ended. For this reason, the mannequin may usually be
monitored for a full 60 seconds, possibly to better measure actual
final total body burns. FIG. 16 may illustrate the effects of the
latent heat and/or its contribution to additional burns after the
three seconds of flame exposure may have ended. That is, a graphic
representation of various sample garment testing results according
to the NFPA 2112 standard with a three second exposure may be seen
in FIG. 16. As is evidenced in the FIG. 16 graph by the continued
upward trend in the percentage of total body burns which may be
sustained after three seconds, both the NOMEX.RTM. and the
INDURA.RTM. closed-texture garments showed the effects of this
residual heat in the fabrics and/or in the air trapped underneath
of them.
[0154] As previously mentioned, DuPont's THERMO-MAN.RTM. mannequin
may be equipped with one hundred and twenty-four (124) heat sensors
which may be distributed over the mannequin body. These heat
sensors may be used to measure the heat which may have been
transmitted from the fire, through the test garments to the surface
of the mannequin. A map of the individual sensor locations may be
seen in FIG. 17. That is, various sensor locations on front and
rear sides of the DuPont THERMO-MAN.RTM. mannequin may be seen FIG.
17. With this map, it may be possible to analyze the 2.sup.nd
and/or 3.sup.rd degree burns that may be expected to occur at any
location on the body. Using it, a person of ordinary skill in the
art would be able to narrow her focus and/or analyze the data
returned from the lower body exclusively, possibly thereby
allowing, in hindsight, such a person to better scrutinize the
protective performance of an open-textured mesh material.
[0155] For the mannequin tests performed according to the
invention, DuPont's THERMO-MAN.RTM. mannequin was dressed in
ventilated work pants as per a preferred embodiment of the
invention that is fully described in detail elsewhere herein. In
brief, the ventilated work pants according to the invention may be
best described as having a solid, closed-fabric upper portion (from
about the knee to the waist) that is securely attached to lower leg
portions (from about the knee to the ankle). The lower leg portions
are predominantly constructed from a substantially open-textured
fabric, such as, for example, an athletic mesh. Solid fabric bottom
cuffs and/or lower side seam reinforcement strips may be exceptions
to the otherwise open-textured construction of the lower leg
portions. Optionally, ventilated work pants may be convertible, and
such convertible ventilated work pants may be worn (i) with a set
of lower leg covers on, or (ii) with them off. Convertible
ventilated work pants may preferably include separate, detachable
solid-woven lower leg covers that can be attached to the uppers at
about the knee, in order to substantially cover the mesh portions
when desired. An image of a pair of convertible ventilated work
pants according to the invention is shown in FIG. 18. More
particularly, FIG. 18 shows a pair of convertible ventilated work
pants, as viewed with a right leg cover thereof removed and with a
left cover thereof partially open.
[0156] For the tests that were performed according to the present
invention, the closed-textured or woven upper portion (from about
the knee up, of the pants was constructed using a standard 6.0 oz.
NOMEX.RTM. IIIA fabric. The lower cuffs, lower side seam
reinforcement straps, and detachable leg covers were also
constructed from this material. The front and back of the lower
legs (from about the knee down) were constructed entirely from the
Tek-Knit 6.0 NOMEX Type 462 mesh, with the exception of the cuffs
and side strips as previously noted. The upper body was dressed for
the tests in a standard plain weave 6.0-7.5 oz, flame-resistant
long-sleeved shirt and, in compliance with ASTM F1930 and NFPA 2112
guidelines, the mannequin was pre-dressed in a T-shirt and briefs
of 100% cotton.
[0157] According to the invention, no fewer than four separate
tests, in total, were run using three different configurations of
the convertible ventilated work pants, All pants tested were of the
same listed size, and were made using the same patterns and methods
of construction. All pants tested were subjected to a more rigorous
4 second exposure. Tests #1 and #2 were conducted with the pants in
the "open mesh leg" configuration; that is, with the open-textured
mesh lower legs exposed to the full force of the simulated flash
fire. Test #3 had the pants in the "full leg covers on"
configuration, meaning that the covers were re-attached over top of
the mesh legs, thereby creating a double fabric layer comprised of
the covers and the underlying mesh legs. Finally, for Test #4, the
lower leg mesh portions were cut off before the solid leg covers
were re-attached, leaving a single layer of solid woven material
(the covers) covering the lower legs. The rationale for the removal
of the underlying mesh portions for Test #4 was perhaps to simulate
a regular pair of single layer secondary NOMEX.RTM. IIIA work
pants.
[0158] FIG. 19 provides a visual representation of the test data,
depicting the lower body burns sustained in test Nos. 1 through 4,
wherein the color brown indicates second degree burns and the color
red indicates third degree burns.
[0159] When analyzing the data from the lower body sensors, and
through not essential to the working and/or utility of the
invention, some conclusions may be immediately drawn. Test #3, with
the double fabric layer comprised of the covers and the underlying
mesh legs, was the best performing tested configuration from a
percentage of body burn perspective. This result may perhaps have
been expected because of the previously mentioned increased TPP
values that may generally be associated with layered
flame-resistant fabrics. The results for Test #3 may be perceived
as vastly superior to the other test results and may generally
indicate that, when the convertible pants according to the
invention are used with their covers on, such as, for example, in
cool weather applications an/or when the need for additional
protection is anticipated, the underlying mesh legs and the layer
of insulating air between the two fabrics may be generally believed
to provide for a much improved level of protection from immediate
burn injury over a single solid-fabric layer (as was tested in Test
#4). It is additionally generally believe, though not essential to
the working and/or utility of the present invention, that residual
heat retained in the fabric of the outer solid lower leg covers may
have played a substantially diminished role in contributing to
additional burning on the lower legs, as these covers were held
away from the skin by the underlying layer of mesh. This conclusion
may draw support in part and/or be evidenced by the fact that the
majority of the burn injuries recorded during Test #3 may be
generally seen to have occurred on the upper legs, where only a
single layer of the solid tightly woven fabric was present.
[0160] While the additional protection that resulted from the
layering effect in Test #3 may, in hindsight, have been predicted
to certain degree, the protective properties demonstrated by the
single-layer of open-textured material in Tests #1 and #2 was both
dramatic and unexpected. FIG. 20 shows a tabulated summary of the
data that was collected from the sensors on the lower mannequin for
Test Nos. 1 through 4.
[0161] Although all three configurations may be generally observed
to have passed NFPA 2112 percentage of body burn minimum standards,
especially when one considers that the exposure time was a more
rigorous 4 seconds, both Test #1 and Test #2 outperformed Test #4
with respect to the total percentage of body burn experienced from
the waist down. More significantly, while the percentage of sensors
that recorded body burns from the knee up remained relatively
consistent for all four tests (substantially in the range of about
20% to about 30%, Test #1 and Test #2 may both be seen to have
outperformed Test #4 with respect to the percentage of burns from
the knee down. The data may generally indicate that improved
performance resulted from a greatly decreased percentage of
2.sup.nd degree body burns experienced in areas covered only by the
open-textured material. Such a conclusion may lead to a corollary
conclusion being made, namely, that the open-textured lower legs
according to the present invention allowed for a venting effect
that may have enabled quick cooling of the garment according to the
invention. This cooling may, in turn, have reduced any additional
burns that might otherwise have resulted, in normal circumstances,
from the residual heat retained in the fabric itself and/or from
the heat trapped next to the skin beneath the closed textured
material. In essence, while the lower TPP rating of the
open-textured mesh material may have allowed for higher initial
3.sup.rd degree burns, the overall effect may have been to reduce
the total combined second and/or third degree body burn percentages
in the areas of the mesh and as a result, possibly to provide an
improved total body burn percentage. It should perhaps be once
again specifically noted that the aforementioned conclusions and
beliefs concerning mechanisms underlying the working of the present
invention are not essential to working and/or utility of same.
[0162] Nonetheless, the potential significance of this
aforementioned venting effect should not be underestimated when it
comes to potential improvements in the protective properties of
flame-resistance clothing. The documentation to date that might
support the existence of this venting effect suggests that single
layer flame-resistant secondary garments, such as, for example,
shirts, pants, and/or coveralls, may be safety-rated and
constructed entirely from open-textured fabrics and/or materials.
Moreover, persons having ordinary skill in the art should
appreciate that the data also suggests that open-textured garments
may, in fact, provide equivalent and even increased protection
against body burns when compared to conventional closed-textured
and/or tightly-woven fabrics. Perhaps more importantly, the
evidence may suggest that these same open-textured materials and/or
fabrics may satisfy the NFPA and ASTM requirements necessary to be
safety-rated as certified fabrics. Such certification would
facilitate the use and/or adoption of open-textured materials an/or
fabrics, either on their own in combination with any other FR
and/or FRT rated fabrics, in single or multiple layers, in any
configuration, on a wide variety of garments in a wide variety of
contexts.
[0163] Of course, combination of closed and open-textured fabrics
could also be used to create either standard or convertible type
garments to suit the specific protective needs of a variety of
different end-users. For example, refinery workers in the southern
U.S., who may be more concerned with flash fires, might opt for
long-sleeved shirt and/or pants and/or coveralls constructed
entirely from mesh. Electric utility workers, on the other hand,
may have an intermittent but frequent need for garments with
increased TPP and/or ATPV ratings, depending on the Hazard Risk
Category of the particular job. In this regard, such utility
workers may prefer to use layered convertible-type garments that
may provide additional protection, when required. As well,
convertible-type garments may provide for superior all-season
applications in certain contexts.
[0164] In will, in any case, be appreciated by persons having
ordinary skill in the art that, according to the invention,
manufacturers may be able to provide end-users with cooler, more
comfortable, and/or lighter weight flame-resistance garments to
satisfy their specific needs.
[0165] In closing, it may be worthwhile to once again note that
various other modifications may be used in the design and/or
manufacture of the article of safety clothing according to the
present invention without departing from the spirit and scope of
the invention, which is, of course, limited only by the
accompanying claims.
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