methods for producing a watermark element, and a blade-shaped substrate with a watermark, watermark element, dewatering screen, security paper provided with one or more watermarks, and , document

摘要

According to one aspect, the invention relates to a method for producing a watermark element (10) for forming a shadow watermark image in a substrate by means of dewatering of a fibrous suspension, wherein the watermark element (10) comprises a body with a relief side (12) having a relief (14) and a dewatering side (16) positioned opposite the relief side, perforations (18) being provided at least in the relief (14), a perforation (18) comprising a channel (20) with a channel inlet (21) at the relief side (12) and a channel outlet (22) at the dewatering side (16), which method includes the steps of forming perforations in a body in a mechanical manner and introducing a relief in the intended relief side, the perforations (18) being formed in such a way that the dewatering capacity, expressed as the open surface area of the channel inlet(s) per unit of surface area of the relief, is dependent on the height (h) of the channel inlet (21) with respect to the dewatering side (16), it being the case that the higher the height, the lower the dewatering capacity.