Problems are often encountered in the printing and packaging industries when running webs of paper or plastics on machines, arising from the friction effect between the web and the turner bars used for altering the direction of web travel.
Many of these web-transport problems may be greatly eased by supporting the web, as it passes over the turner bar, on an externally pressurized air-bearing, and thus virtually eliminating the friction effects. The paper presents details of the design of an air-blown porous-metal turner bar suitable for this purpose. Advantages to be gained from the installation of such bars, together with their limitations in use, are discussed.
