Corrugator (Single-Facer)

Overview

The single-facer is the part of a corrugated-board line that forms the fluted medium and bonds one liner to it, producing single-faced board that a downstream double-backer later faces on the other side into the familiar boxboard. It is where the cardboard box really begins: flat rolls of kraft liner and medium go in, and a continuous web of fluted, glued, single-faced board comes out to be slit, scored, and cut to sheets. Paper is conditioned at the Preheater, fluted in the Corrugating Roll Unit, glued at the Glue Unit, and bonded in the Pressure/Belt Section.

The flutes do the structural work: by standing the medium up in a wave between flat liners, the board gets stiffness and cushioning at very low weight, and swapping the Fluted Corrugating Roll pair changes the flute size for thicker or finer board.

How it works

Each web of paper first wraps a steam-heated Preheater drum to bring it to temperature and set its moisture so it flutes without cracking and bonds without blistering. The medium then passes between the two meshing rolls of the Corrugating Roll Unit, which press it into the flute profile, held in the wave by vacuum or fingers as it comes off the roll.

The Glue Unit runs an applicator roll in a starch pan and lays a thin film of adhesive onto just the flute tips. The flat liner meets the glued tips in the Pressure/Belt Section, where a heated plate and pressure belt hold the two together long enough for the starch to gel and bond. The finished web is trimmed and creased by the Slitter-Scorer and chopped to sheet length by the Cutoff Knife, whose servo phases each cut to the scored pitch. The Control System holds the preheat temperatures, glue rate, and line speed, and phases the slitter and cutoff to the order.