Web processing roll having directional vacuum ports

A web processing roll for handling a web of material using vacuum, comprising:

• a roll body extending axially between first and second ends and configured to rotate about a rotational axis extending between the first and second ends;
• the roll body defining an outer periphery against which the web of material is held;
• the roll body defining a vacuum passage extending axially therein providing axial air flow, the vacuum passage being positioned radially inward from the outer periphery;
• first and second vacuum holes fluidly connected to the vacuum passage and extending through the outer periphery and positioned to provide vacuum proximate the outer periphery of the roll body to hold the web of material against the outer periphery with vacuum supplied to the first and second vacuum holes by the vacuum passage;
• the first vacuum hole being positioned axially along the rotational axis closer to the first end than the second vacuum hole, the first and second holes being positioned axially between the first end and an axial center of the roll body;
• the first vacuum hole having a first inlet end and a first outlet end, the first outlet end being at the intersection of the first vacuum hole with the vacuum passage;
• the first vacuum hole defining a first flow path extending from the first inlet to the first outlet;
• the first flow path extending at a first angle that is non-perpendicular to the rotational axis and is directed, at least in part, axially toward the first end at the first outlet end of the first vacuum hole;
• the first flow path extending at a second angle relative to the rotational axis proximate the inlet end that is closer to perpendicular than the first angle;
• wherein vacuum produced by the first vacuum hole is less than vacuum being produced at the second vacuum hole.

A vacuum hole insert for use with a processing roll for handling a web of material using vacuum, the processing roll having a roll body extending axially between first and second ends and configured to rotate about a rotational axis extending between the first and second ends, the roll body defining an outer periphery against which the web of material is held, the roll body defining a vacuum passage extending axially therein providing axial air flow generally parallel to the rotational axis, the vacuum passage being positioned radially inward from the outer periphery, the vacuum hole insert comprising:

• at least one first vacuum hole configured to be fluidly connected to the vacuum passage and to extend through the outer periphery and positioned to provide vacuum proximate the outer periphery of the roll body to hold the web of material against the outer periphery with vacuum supplied to the at least one first vacuum hole by the vacuum passage when mounted to the roll body;
• the at least one first vacuum hole having a first inlet end and a first outlet end, the first inlet end being at an intersection of the at least one first vacuum hole with the outer periphery, when mounted to the roll body, and the first outlet end being at the intersection of the at least one first vacuum hole with the vacuum passage, when mounted to the roll body;
• the at least one first vacuum hole defining a first flow path extending from the first inlet to the first outlet;
• the first flow path extending at a first angle that is non-perpendicular to the rotational axis and is directed, at least in part, axially toward one of the first and second ends at the first outlet end of the at least one first vacuum hole, when mounted to the roll body;
• and
• the first flow path extending at a second angle relative to the rotational axis proximate the inlet end that is closer to perpendicular than the first angle, when mounted to the roll body.

A method of handling a web of material on a processing roll using vacuum, the method comprising:

• supplying vacuum within a vacuum passage within a roll body of the processing roll having a rotational axis extending between first and second ends;
• supplying vacuum to an outer periphery of the roll body through vacuum holes fluidly connecting the vacuum passage with the outer periphery;
• wherein:
• at least one of the vacuum holes having a first inlet end and a first outlet end, the first inlet end being at an intersection of the at least one vacuum hole with the outer periphery and the first outlet end being at an intersection of the at least one vacuum hole with the vacuum passage;
• the at least one vacuum hole defining a first flow path extending from the first inlet to the first outlet;
• the first flow path extending at a first angle that is non-perpendicular to the rotational axis and is directed, at least in part, axially toward one of the first and second ends at the first outlet end of the at least one vacuum hole;
• the first flow path extending at a second angle relative to the rotational axis proximate the inlet end that is closer to perpendicular than the first angle;
• directing air passing through the at least one of the vacuum holes due to the vacuum in the vacuum passage axially towards, at least in part, an end of the roll body due to the first angle of the first flow path at the first outlet end of the at least one vacuum hole.