Central impression drum printing machine for printing radiation curable inks

摘要

The printing machine (50) comprises a central impression drum (35) supporting a web substrate (S), several printing groups (51-55) arranged around an entry side (35a) and several printing groups (56-60) arranged around an exit side (35b) of the central impression drum for applying radiation-curable inks on the web substrate (S), and at least one curing unit (61-69) arranged between each pair of adjacent printing groups. The first curing unit located in a larger space between the first printing group (51) and the subsequent printing group (53) and/or the last curing unit located in a larger space between the last printing group (60) and the preceding printing group (58) is an extensive curing unit (61, 69) providing an exposure time to ultraviolet radiation longer than the remaining curing units (63-67).