SAFETY PAPER PRODUCTION METHOD

摘要

The invention relates to methods for producing a safety paper which is used for producing fraud-proof printing products. In the first embodiment, a method for producing a safety paper comprises the steps of: forming a paper web with a security strip having a width of more that 2 mm and being embedded into this web during the molding thereof on a wire-mesh cylinder, wherein the safety strip is introduced into a pulp in such a way that, prior to contact thereof with the cylinder, a fibrous layer is molded, except for areas on a cylinder surface where the layer is not formed for lack of filtering property. The security strip is positioned on the cylinder in such a way that a part of the surface thereof coincides with cylinder elements where the layer is not formed, and free access zones are formed as windows on a paper wire side. Areas devoid of filtering property are created on the cylinder surface by covering the wire mesh with a filigree paper or by pouring the wire mesh with a waterproof material or by making through holes in the wire mesh. The security strip is completely or partially exposed at a side opposite to a wire side, while through windows are formed at locations where the windows on the wire side and the complete or partial outs of the security strip on the opposite side of paper coincide. In the second, third and fourth embodiments, the method for producing a safety paper comprises the step of forming a paper web with a security strip of more than 2 mm in width thereby to provide outs of the security strip onto both sides of the paper web so as to obtain a through window effect.