Abstract: A filter element formed of a pleated filter medium (11) and having a seal or gasket element (15) on its periphery or end faces. On one side of the filter element, which may represent either the inlet or the outlet side of the filter element, at least one adhesive track or reinforcing member (12, 13, 14), and preferably at least two adhesive tracks or reinforcing members (12, 13, 14), is/are arranged in such a way that the filter element can be bent to a curved configuration in one direction.

Abstract: The present invention relates to a fresh air filter that comprises a highly air-permissive two- or three-dimensional support made of a cross-linked polymeric foam which includes pores of large dimensions. The support comprises joining portions which are coated with a layer of ion-exchange globules.

Abstract: A process for producing activated carbon granules in which (a) a mixture of distillation residues from isocyanate production, a carbon-containing processing auxiliary substance, and optionally one or more other additives is shaped into flowable granules; (b) the resulting granules are then carbonized at low temperatures, and (c) the carbonized product is activated. The activated carbon granules produced in this way can be used to manufacture adsorbent substrate structures loaded with this product, in particular adsorption filters, filter mats, odor filters, surface filters for protective suits against chemical poisons, and ambient air purifying filters.

Abstract: A filtering material with adsorbing properties which comprises a flat carrier, the carrier being provided on one or both sides with a binder coating which becomes tacky when heated and to which an adsorption material is adhered. An adsorption filter can be produced from at least two layers of the filtering material. The invention also relates to a process for producing the filtering material.

Abstract: A method of processing spent ion-exchange resins contaminated with suspended particles, inorganic residues and/or organic foreign matter so as to render the resin ineffective for continued use, by which method this waste material can be processed to produce useful activated carbon particles instead of simply being dumped in a landfill. In accordance with the invention, granular spent organic ion-exchange resin having an ash content of from 5 to 30% is first dried, then carbonized under a substantially inert atmosphere at a temperature of 300 to 900° C., the inert atmosphere containing 0.2 to 4 volume percent oxygen up to 400° C., and finally activated at a temperature of at least 700° C. under a substantially inert atmosphere containing 3 to 50 volume percent steam.

Abstract: Granulated activated carbon is produced by an improved process which involves carbonizing pellets of a styrene-divinyl benzene copolymer matrix with concentrated sulfuric acid at temperatures up to at least 750.degree. C., followed by activation at temperatures of 800.degree. C. to 900.degree. C.