Web slitters with a gaseous passageways bar and/or methods of operating web slitters

摘要

A web slitter comprises a bar (1, 13, 19, 23, 28, 35, 39, 44, 50); one or more slitting members (9, 27, 43, 48, 49) which, in use, are held in a position to slit a web (26, 42) as it is drawn over said bar (1, 13, 19, 23, 28, 35, 39, 44, 50); said bar (1, 13, 19, 23, 28, 35, 39, 44, 50) incorporating an outer portion (5,15, 31) with gaseous passageways located under said web; said bar being equipped with or being connectable to means for pressurising gas through said gaseous passageways in order to provide a gaseous cushion between said bar (1, 13, 19, 23, 28, 35, 39, 44, 50) and said web (26, 42); characterised in that said bar further comprises a longitudinal strip which extends width wise under said web; said strip being of a non-porous material; said portion (5, 15) which extends under said web (26, 42) incorporating outside of said strip an array of uniformly distributed gaseous passageways.