| GB1127581A | 1968-09-18 | |||
| EP0037745A1 | 1981-10-14 | |||
| US3586596A | 1971-06-22 |
| 1. | A protective clothing against skin penetrating means of chemical warfare and skin irritant industrial gases, c h a r a c t e r i z e d i n that it comprises an outer drop barrier constructed with a carrier which may be a textile fabric having a micro porous watertight film open to diffusion laminated onto it, and an absorbing layer, e. g. a carrier known per se and coated with an absorbant, e.g. activated carbon, or a foamed material impregnated with a similar absorbing material, which absorbs the vapors of toxic substances that penetrate the drop barrier, and where the drop barrier has its textile fabric outside to offer'. good protection against mechanical stress, which fabric may if desired be impregnated or dyed in order to impart e.g. a flame baffling or camouflage effect to the outside. |
| 2. | A protective clothing as stated in claim 1, c h a r a c t e r i z e d i n that there is an air layer between the drop barrier and the inner gas absorbing layer. |
| 3. | A protective clothing as stated in claim 1, c h a r a c t e r i z e d i n that the outside drop barrier and the gas absorbing layer are constructed into one layer. |
| 4. | A protective clothing as stated in claim 1, c h a r a c t e r i z e d i n that the drop barrier and the gas absorbing layer form two separate units. |
| 5. | A protective clothing as stated in claim 1, c h a r a c t e r i z e d i n that the micro porous film on the drop barrier is white to protect against heat radiation. |
The present invention relates to a protective clothing system which combines high protective ability against skin penetrating means of chemical warfare, good airtightness and watertightness with low physiological strain on the user.
The previously known air permeable protective suits have a composition resulting from a compromise between different requirements, as:
High protective capability against skin penetrating means of chemical warfare or other skin irritants, and the requirement that the soldier should be able to keep up physical activities during a certain period of time.
such a suit is described in NO-PS 128 694 which corresponds to US-PS 3 818 507.
Chemical protection 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 intercept drops and pre¬ vent liquid from penetrating 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 outer layer cannot be made so dense that it completely prevents large drops striking the outer layer with high velocity from penetrating the drop barrier. In such cases the liquid will rapidly saturate the absorption layer beneath eliminating the protective effect of the suit.
Said suits only offer sufficient protection when used outside the normal field service uniform, and they must be replaced by new ones a certain time after contamination.
The present invention provides a clothing system which to a high degree- solves several of the problems of the known air permeable protective suits.
Said suit comprises a drop barrier outside a gas barrier, separated by an air layer.
Said drop barrier consists of a micro porous membrane that is laminated with a carrier fabric, the carrier fabric form¬ ing the outside. The carrier fabric imparts wear resistance and mechanical stability to the outer layer and may be treated so as to provide the suit with other qualities, as colour, flame baffling, etc. Said micro porous membrane has pores of such a magnitude that they let through water vapor., but not water, so as to provide good 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 that could otherwise be forced through the outer layer. Due to the fact that said micro porous membrane keeps the drops back in the outer layer, the outer fabric may be subjected to a treatment that makes drops spread over a larger surface area. Evaporation to the atmos¬ phere is, thus, enhanced, the load on the absorption layer :. * = inside is reduced and the hazard of contact, which the contaminated surface constitutes, is considerably reduced.
By a micro porous membrane is meant a film, e.g. a polytetra- fluoroethylene, polyethylene, polyurethane film having throug pores of a magnitude of 0.1-3.0 μ, a pore number of 0.5 x 106 g
- 1.5 x 10 /cm, water vapor permeability: approx. 3000
2 g/m /24h, and showing no indications of penetration measured according to ISO/DIS 6530
If protection against heat radiation is desired, this may be achieved by the use of a micro porous membrane having a high- melting point and a white colour for good heat reflection.
Underneath the outer layer/micro porous membrane the normal gas barrier is provided. The drop barrier and the gas barrie may be two separate pieces of clothing that can also be re¬ placed separately. The system does not require use of the regular field service uniform to provide the necessary protection.
The advantages of the present invention as compared with the previously known systems are that the micro porous membrane imparts considerable water vapor transmission to the suit and, thus, low physiological strain on the user.
The resulting suit is airtight and watertight.
It provides very high protection against means of chemical warfare due to the fact that drops cannot penetrate to the absorbing layer beneath, even under pressure. The absorbing layer is only subjected to vapors from liquid deposits on th 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 reduces the load totally as well as- locally on the gas barrier. The lifetime of the absorbing layer is increased.
Spreading of drops on the outer layer results in consider¬ able reduction of the contact hazard which the contaminated surface of the suit would otherwise constitute. This has considerable operative advantages.
The outer fabric and the absorbing layer being impregnated to a flame baffling state and the micro porous membrane at the same time having a high melting point and excellent heat reflection due to its white colour, protection against pyrotechnical weapons and heat radiation ' has been achieved as well.
The suit does not require the normal field service uniform to be worn underneath to impart the necessary protection.
The principle of the micro porous membrane for a drop barrie over an absorption layer may also be utilized for protection of hands and feet against chemical warfare and at the same time to transport perspiration.
The invention is not exclusively intended for military use; it may also be useful for protective suits e. g. in indust¬ rial and similar environments.