Note: Descriptions are shown in the official language in which they were submitted.
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T]le preSell-t illVellt-iOIl relatcs to a protective clothing
system which combines hicJh protec-tive ability ayains-t skin
penetrating means oE chemiccll warEare, good airtightness and
wa-tertigh-tness wi-th low physiological strain on the user.
The previously known air permeable protective suits have a
composition resulting from a compromise between differen-t
requirements, as:
lligh protective capabili-ty against skin penetrating
means of chemical warfare or other skin irritants,
and the requirement that the soldier shouJd be able
to keep up physical activities during a certain
period of time.
Such a suit is described in NO-PS 12~ 694 which corresponds
to US-PS 3 813 507.
Chemical pro-tection is essentially achieved by use of two
barriers, a drop barrier and a gas barrier. The outer layer
of the suit, its drop barrier, will intercep-t drops and pre-
ven-t liquid from pene-trating further into the clothing
system. The vapors from drops deposited on the outer layer
will diffuse into -the suit and are intercepted by the gas
barrier, an absorbent, e.g. bonded activated carbon. The
two barriers are separated by an air layer.
Since it is also desirable to make the suit highly permeable
to water vapor in order to reduce the physiological strain
on the soldier, the fabric of the ou-ter layer cannot be made
so dense tha~ it completely prevents large drops striking
the outer layer with high velocity Erom penetrating the drop
- barrier. In such cases the liquid will rapidly saturate the
absorption layer beneath eliminating the protec-tive effect
of the suit.
Said suits only offer sufficient protection when used outside
the normal field service uniform, and -they mus-t be replaced
by new ones a certain time after con-tamination.
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The presel1t inventLol1 provi(les a cLothil1cJ system which -to a
high degree solves several of -the prohlems of -the known air
permeable protective suits.
Said suit comprises a drop barrier outside a gas barrier,
separa-ted by an air layer.
Said drop barrier consists of a micro porous membrane tha-t
is laminated with a carrier fabric, the carrier fabric form-
ing the outside. The carrler fabric imparts wear resistance
and mechanical stability to the ou-ter layer and may be
treated so as to provide the sui-t wi~h other qualities, as
colour, flame baffling, etc. Said micro porous membrane has
pores of such a maynitude that they let throucJh water vapor,
but not water, so as -to providecJoc~d water vapor -transmission
and enable the soldier to ventilate excessive heat. At the
same time said membrane will completely prevent liquid from
penetrating the outer layer - even large drops having high
collision energy and drops -tha-t could otherwise be Eorced
-through the outer layer. Due to the fact -that said micro
- -- porous membrane keeps the drops back in the ou-ter layer, the
outer fabric may be subjected to a -treatment tha-t makes drops
spread over a larger surface area. Evapora-tion to -the atmos-
phere is, thus, enhanced, the load on -the absorption layer -
inside is reduced and the hazard oE contact, which the
contaminated surface constitu-tes, is considerably reduced.
By a micro porous membrane is mean-t a film, e.g. a polytetra-
fluoroethylene, polyethylene, polyurethane film having through
30 pores of a magnitude of 0.1-3.0 ~L, a pore number of 0.5 x 106
- l.5 x lO9/cm, water vapor permeability: approx. 3000
g/m2/2~h, and showing no indications of penetration measured
according to ISO/DIS 6530.
If protection against heat radiatiol1 is desired, this may be
achieved by the use of a micro porous membrane having a high
melting point and a white colour for ~ood heat reflec-tion.
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Underneath the outer layer/lllicro yorous membra11e -the normal
gas barrier is provided. 'rhe drop barrier and the gas barrier
may be two separate pieces of clothing that can also be re-
placed separa-tely. The system does not require use of -the
regular field service uniform to provide the necessary
pro-tec-tion.
The advantayes of -the present invention as compared with the
previously known sys-tems are -that -the micro porous membrane
imparts considerable water vapor transmisslon to the suit
and, thus, low physiological strain on -the user.
The resul-ting suit is airtigh-t and watertight.
It provides very high protection agains-t means of chemical
warfare due to the fac-t that drops canno-t penetrate -to the
absorbing layer beneath, even under pressure. The absorbing
layer is only subjected to vapors from liquid deposits on -the
outer layer.
~- - The micro porous membrane permits the outer layer to be pro-
vided with an impregnation that will spread drops of means
of chemical warfare on -the outside of -the suit. In this man-
ner evaporation -to the atmosphere is enhanced, which red~ces
the load to-tally as well as locally on the gas barrier. The
lifetime of the absorbing layer is increased.
Spreadiny of drops on the outer layer results in consider-
able reduction of the contact hazard which the contaminated
surface of the sui-t would otherwise constitute. This has
considerable operative advan-tages.
The outer fabric and -the absorbing layer being impregnated
to a flame baffling sta-te and the micro porous membrane
at the same time having a high mel-ting point and excellent
heat reflection due to its white colour, protection against
pyrotechnical weapons and hea-t radia-tion has been achieved
as well.
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The sui-t does not requ:ire the norma] field service uniEorm
to be worn underneath to impart the necessary pro-tection.
The principle of the micro porous membrane for a drop barrier
over an absorp-tlon layer may also be utill~ed for protection
of hands and feet against chemical warfare and at the same
time to transport perspiration.
The invention is not exclusively in-tended for military use;
0 it may also be useful for protective suits e. g. in indust-
rial and similar environments.
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