Bearers - A Necessary Evil?

Press bearers are hardened steel rings at the ends of printing cylinder bodies; they are used on both sheet and web offset presses and are thought to be essential for high quality printing. However, many presses have been designed which perform well without bearers. The authors describe the first phase of a research program initiated to provide a comprehensive, quantitative theory on the relationship between bearers and printing impression; they discuss cylinder vibrations, computer-aided simulation of bearer wear, correct bearer preload, and electronic monitoring during production.