Producing fibrous jet with element of specific thickness, for use in security sheets or documents, is carried out on papermaking machine forming cloth with reduced dripping tendency region

摘要

In the wet-process production of a fibrous jet, having element(s) of specific thickness, on a papermaking machine forming cloth consisting of a surface cloth stacked with subcloth(s), by dripping an aqueous fiber suspension onto the cloth, the stack has a a region (in the subcloth(s) and/or under the surface cloth) of reduced dripping tendency relative to the surface cloth. The reduced dripping region corresponds with the position of formation of the element. Independent claims are included for: (1) the papermaking machine forming cloth as above, with the reduced dripping tendency region; (2) the production of the cloth, by forming the reduced dripping tendency region using an appropriate cloth fragment or perforated body; (3) a security sheet having at least one fibrous jet formed by the present process; and (4) a security docement containing the sheet.