Cross cutting
The printed web is perforated and  cut in the signature folder. Cutting  and perforation knives are situated  in the same cylinder, set at 180° to  one another. The high performance cutting cylinder automatically adjusts itself to the required section length  and ensures a precise cutting position  for each individual signature with  a dynamic control.

Folding
Even for folding, proven high perform-ance technology taken from offset printing is put to use in the Sigma- Folder. The web is folded longitudinal over a former folder before the cross cutting. Depending on the arrangement of the printed book pages on the web, folding is done either symmetrically or asymmetrically. After cutting, a cross fold and another length fold are applied using rotating chop-fold technology.  All folded edges are perforated. The SigmaFolder is fully automated. 8, 12 or 16-page signatures can be produced in order to make optimum use of the web width.