Improvement of web spacing characteristics by two types of guide rollers

摘要

In the manufacturing fields of plastic sheet, paper, magnetic tape, thin metal plate, photographic film etc., the web transporting systems supported by guide rollers are often used. In such systems, it is of cardinal importance to control the web spacing between the traveling web and guide rollers. For example, when the guide roller is used as turn bar in the commercial web offset press or used as dryer in the coating processes of web, it is sometimes needed to keep sufficient air film thickness between web and roller for avoiding the web defects due to surface roughness, stain and lack of uniforming. On the other hand, when the guide roller is used as drag roller, it is desirable to remove the entrained air between web and roller for keeping enough level of traction.