Apparatus and method for applying a viscous liquid to a material surface

A method for applying a viscous liquid to a material surface comprising the steps of:

• (1) applying a continuous layer of the liquid to the surface of a rotating cylindrical applicator roll;
• (2) mounting a metering doctor blade with a blade edge in contact with the liquid layered surface of the roll;
• (3) orienting the blade edge to extend in the upstream direction and provide a reverse angle of attack with respect to the applicator roll;
• (4) providing the blade edge with spaced notches separated by straight edge portions to create spaced parallel beads of the liquid separated by annular roll surface portions with essentially no liquid thereon;
• (5) mounting a spreader blade with a continuous blade edge in contact with the bead-carrying roll surface downstream of said metering blade to spread the liquid beads into a layer of selected thickness;
• and,
• (6) moving the material to bring the material surface into generally tangential contact with the roller surface to transfer the liquid to said surface.

A method for applying a viscous liquid to a moving material surface comprising the steps of:

• (1) providing a liquid supply;
• (2) mounting a rotatable cylindrical applicator roll with an outer surface portion in operative communication with the supply to pick up the liquid;
• (3) positioning a metering doctor blade to engage the outer surface of the applicator roll downstream of the liquid supply with respect to the direction of roll rotation;
• (4) providing said metering blade with a roll-engaging edge defined by a series of spaced notches separated by straight edge portions;
• (5) orienting said metering blade with the edge in the upstream direction to provide a reverse angle of attack;
• (6) rotating said roll to form a series of spaced parallel beads of liquid along the roll outer surface and to wipe essentially all of the liquid from the roll surface between the beads;
• and,
• (7) spreading said liquid beads laterally across the roll surface and moving the material surface generally tangentially along and in contact with the roll surface in the direction of rotation to transfer the liquid to the surface.

An adhesive applicator apparatus for applying a liquid adhesive to a moving web comprising:

• an adhesive supply;
• a cylindrical applicator roll rotatably mounted with an outer surface portion in operative communication with the supply to pick up liquid adhesive;
• a metering doctor blade positioned to engage the outer surface of the applicator roll downstream of the adhesive supply with respect to the direction of roll rotation, said metering blade having a roll-engaging edge defined by a series of spaced notches separated by straight edge portions, said notches adapted to form a series of spaced parallel beads of adhesive along the roll outer surface and said edge portions adapted to wipe the adhesive from the roll surface between the beads;
• and,
• means downstream of said metering blade for spreading said adhesive beads laterally across the roll surface and for moving the web generally tangentially along and in contact with the roll surface in the direction of rotation to transfer the spread adhesive to the web.

A method for applying a liquid adhesive to the flute tips of a corrugated paper web comprising the steps of:

• (1) applying a continuous layer of the adhesive to the surface of a rotating cylindrical applicator roll;
• (2) mounting a metering doctor blade with a blade edge in contact with the adhesive layered surface of the roll;
• (3) providing the blade edge with spaced notches separated by straight edge portions to create spaced parallel beads of adhesive separated by annular roll surface portions with essentially no adhesive thereon;
• (4) mounting a spreader blade with a continuous blade edge in contact with the bead-carrying roll surface downstream of said metering blade to spread the adhesive beads into a layer of selected thickness;
• and,
• (5) moving the web to bring the corrugated flute tips into generally tangential contact with the roller surface to transfer the adhesive to said flute tips.