Abstract: A process for the production of flexible surface filter material for dealing with noxious substances is described, in which a foam layer impregnated with a paste containing active particles is simultaneously joined to a preferably textile carrier layer and heavily compressed during the operation of joining it to the carrier layer. That produces a surface filter material which is highly suitable for use for protective clothing in particular because of its comparatively low level of thermal insulation, while the material is also distinguished in comparison with known materials by activity relative to noxious substances, which is uniform over the entire surface thereof.

Abstract: To produce a flexible material comprising a carrier with active particles fixed thereon by adhesive points, the adhesive points are applied to the carrier when the carrier is of larger area than in its final condition, whereby the adhesive points with active particles adhering thereto are brought closer together in the final condition of the material than when the adhesive points were initially applied.

Abstract: A multi-layer protective breathing mask adapted to cover the mouth and the nose of a wearer thereof comprises an outer layer, an inner layer and, between the outer and inner layers, a filter element comprising a particle filter and an adsorber filter. The adsorber filter may comprise one or more layers of foam material and the layers of foam material may be of different porosities. The at least one layer of foam material adsorber particles which may preferably be of a plurality of particle sizes.

Abstract: In a process for the production of a filter material comprising an open-pore foam carrier carrying adsorber particles of different particle sizes secured thereto, an adhesive is applied to the foam carrier material and then first adsorber particles are applied to the foam carrier material and into the open pores thereof. When the adhesive is still in a non-set condition, second adsorber particles which are of substantially smaller size than the first adsorber particles are then applied to the foam carrier material and into the open pores thereof.