As water drains through the wire, the sheet surface changes from a shiny film of water to a matte look where it is no longer flooded. Operators watch the dry line for position and straightness: a line that moves or bends signals a change in freeness, consistency, vacuum or stock temperature. A crooked dry line often foretells a basis weight or moisture streak.
Dry line moved up two suction boxes since the pulp change, the stock is draining faster.
Also heard as
- water line
- wet line
Related terms
Wire
Endless woven plastic fabric on which the paper web is formed and drained.
Fourdrinier
Paper machine design in which stock drains on a single, horizontal moving wire to form the sheet.
Headbox
Pressurized box that spreads stock in a thin, even jet across the full width of the forming wire.
Formation
How evenly fibers are spread through a paper sheet, judged by small-scale variation in mass.