Abstract: Expanded graphite sealing rings having particles of PTFE captured at least in a surface layer are disclosed. The sealing rings are produced by impregnating porous rings, cut from a sheet of low density expanded graphite, with a PTFE dispersion and then compressing the rings to a desired final density. Impregnation is accomplished in the presence of an electric field.

Abstract: Cutting device in folding apparatus of a rotary printing machine for forming a second longitudinal fold in foldable items, the folding apparatus having a folding blade disposed parallel to a travel direction of the foldable items and disposed in the middle of the items and between two folding rollers located below the folding blade, and a paddle wheel disposed downstream of the folding blade in the travel direction for receiving and depositing the folded items on a delivery belt, the cutting device includes means defining cutting grooves formed in an outer cylindrical surface of one of the folding rollers, a cutting roller associated with and disposed adjacent to the one folding roller and carrying cutting knives adjustable in position with respect to the cutting grooves, both of the folding rollers being formed on the outer cylindrical surfaces thereof with recesses wherein respective conveyor belts are received, the conveyor belts having respective strands superimposed on one another, the superimposed stran