Patent ID: 6241854
Filing Date: 2001-06-05
Classification: D21F,Y10S

Abstract:
In a papermaking machine, a method of sealing a juncture between a vacuum box and a perforated cylindrical shell of a suction roll, the vacuum box being disposed within the perforated cylindrical shell that is rotatable around the vacuum box, the vacuum box having a width and a U-shaped slot extending the width, and the cylindrical shell having an inside surface, the method comprising:(a) providing a composite sealing strip having a length, width and height, and opposing base and contact edges; the strip being sized to be disposed within the U-shaped slot with the length of the strip extending the width of the vacuum box; the contact edge having a surface adapted to engage the inside surface of the cylindrical shell to form a seal;the entire contact edge surface of the sealing strip composed of a substantially uniform composite blend of effective amounts of about 10-25 wt-% nitrite rubber, about 25-45 wt-% graphite, about 5-15 wt % carbon black and a lubricating agent selected from the group consisting of about 0.1-10 wt-% silicone oil or a combination of about 1-10 wt-% silicone oil and about 1-30 wt-% polytetrafluoroethylene, in amounts effective to provide the contact edge of the sealing strip with a low coefficient of friction when placed into contact with the inside surface of the cylindrical shell and as the shell rotates against the contact edge of the sealing strip;(b) inserting the sealing strip into the U-shaped slot of the vacuum box with the contact edge extending out of the slot; and(c) engaging the contact edge of the sealing strip against the inside surface of the cylindrical shell to form a seal effective to provide suction of a fluid through the perforations of the cylindrical shell into the vacuum box as the cylindrical shell rotates about the vacuum box;wherein the contact edge of the sealing strip provides a low coefficient of friction of about 0.02-0.06 against the inside surface of the rotating cylindrical shell.