GRID OF ROUND GRID-TYPE PAPERMAKING MACHINE FOR MANUFACTURE OF FORGERY PROTECTED PAPER, METHOD FOR MANUFACTURE OF FORGERY PROTECTED PAPER, AND FORGERY PROTECTED PAPER Russian patent published in 2007 - IPC D21F1/44 B41M3/10 D21F11/00 

FIELD: production of paper for banknotes, securities, identity certificates or other protected printed products.

SUBSTANCE: grid has filigree members fixed on grid and designed for local reducing of paper water loss for producing of filigree watermark on paper. Filigree members are made in the form of various figures, patterns, or text produced by shaped cutting from sheet material. There are through apertures and/or slots provided in body of filigree member, said apertures having cross size below 500 micron and being designed for creating zones with higher water loss. Method involves forming paper web on grid of round grid-type papermaking machine; dehydrating during pressing of paper web; forming paper on grid in order to produce filigree watermark having additional picture provided on the background of filigree watermark and having higher optical density as compared to optical density of filigree watermark.

EFFECT: increased degree of protecting paper from forgery.

4 cl, 3 dwg