Method for folding optionally overlapping sheets comprises gradually increasing folding force by reducing nip between folding rollers and then activating e.g. vacuum rollers

摘要

The method for folding optionally overlapping sheets (13) comprises a first stage in which the nip between the folding rollers (1, 2) is adjusted so that the sheets are not compressed as they are fed into the pocket (7) and up to the stop (12). The nip is then reduced to give frictional coupling between the rollers and sheets. Finally friction increasing conveyors, vacuum rollers, etc. are activated to increase the force for folding the sheets. An independent claim is included for a machine for use in the method.