METHOD AND DEVICE FOR PRODUCING A SECURITY PAPER HAVING TWO WINDOW SECURITY ELEMENTS

The invention relates to a device (10) for producing a security paper having at least two endless visible window security elements on opposite sides of the security paper, comprising a first paper layer production device (12) for forming a first paper web (20) and for introducing a first endless security element (22) as a window security element into the first paper web (20) during the formation of sheets, a second paper layer production device (14) for producing a second paper web (30), a take-off belt (16) for merging the second paper web (30) with and fixedly joining the second paper web to the first paper web (20), an apparatus for feeding a second endless security element (32) between the first and second paper webs as the paper webs (20, 30) are merged, and a suction device (50) for removing paper fibers from the second paper web (30) in the yet moist state. The invention further relates to an associated method and to a corresponding multi-layer security paper and document of value.