Abstract: A multi-ply paper web is formed by bringing a top ply liner into ply-bonding engagement with a base ply web (W.sub.B) traveling on a base ply forming wire (36). The top ply liner (W.sub.T) is formed between two co-running forming wires (10, 20) in a convex upwardly/concave downwardly curved, substantially horizontal forming zone. Dewatering in the forming zone is effected by applying sub-atmospheric air pressure solely beneath the lower surface of the top ply liner (W.sub.T) being formed. Water is removed from the upper surface of the top ply liner (W.sub.T) solely by wire tension, gravity and centrifugal force created by passing the co-running forming wires (10, 20) over the convex upwardly curved path of travel. This permits a greater concentration of pulp stock fines to remain in the upper surface of the top ply liner (W.sub.T) to effect greater ply-bonding affinity with the base ply (W.sub.B) when the two plies (W.sub.T, W.sub.B) are brought together and bonded.

Abstract: A method and apparatus for continuously forming a multi-ply corrugated container board from freshly laid web plies by simultaneously forming the separate plies from aqueous slurries of fibers on corresponding foraminous fabrics, and dewatering each of them sufficiently to form a web ply capable of being handled in a papermaking machine as an integral web. All of the webs are formed on a single papermaking machine, but separately. The first web ply is laid on a traveling forming wire, such as a fourdrinier wire, and each subsequent web ply is formed in close proximity to the traveling forming wire and brought into bonding engagement seriatim with the top surface of the previously formed web ply carried on the traveling forming wire.A typical corrugated box board has three plies with the inner ply being corrugated.