FIELD: fire fighting means.
SUBSTANCE: this invention is used for respiratory protection from airborne particles and/or unpleasant or toxic gases. Flat, if stowed, folded face mask is made with the ability of its unfolding to the bowl-shaped form to fit over the mouth and nose of the user. The mask comprises at least one porous layer, and at least one stiffening element. Porous layer comprises the first and the second main surfaces, and forms at least one fold. Moreover, the porous layer is made with the ability of its unfolding by at least partial unfolding of at least one fold. The stiffening element is located next to at least a part of the first main surface of the porous layer and comprises a sheet material which consists of an inner part bounded by the perimetre. And at least at two places along the perimetre of the stiffening element there are elements of engagement. Each element of engagement enables the adjacent part of the porous layer to make a shift in the direction in general outwards relative to the inner part of the stiffening element and prevents shifting of the adjacent part of the porous layer in the direction in general inwards toward the inner part of the stiffening element.
EFFECT: mask design provides the required degree of unfolding with increased resistance of the mask unfolding against deformation and folding.
26 cl, 18 dwg
