Apparatus for forming multi-ply fibrous sheets

Apparatus for forming a multi-ply sheet of paper or paperboard comprising:

• means for dry-laying a first web including essentially cellulosic fibers by depositing dry fibers in an air stream onto a movable forming surface,
• means for applying adhesive or binder to the said dry fibers of the first web, means for adding water to the first web to moisten the same to permit consolidation thereof, means including a pair of rolls defining therebetween a press nip through which the first web passes for simultaneously heating the web to a temperature of at least 150.degree. F and pressing the web to a pressure of at least 50 pounds per square inch, whereby the combination of heat, moisture, binder and pressure cause the first web to consolidate by activation of the adhesive or binder into a consolidated self-sustaining sheet of paper or paperboard,
• means for dry-laying a second web including essentially cellulosic fibers by depositing dry fibers in an air stream onto a movable forming surface,
• means for applying adhesive or binder to the said dry fibers of the second web, means for adding water to the second web to moisten the same to permit consolidation thereof, means including a pair of rolls defining therebetween a press nip through which the second web passes for simultaneously heating the web to a temperature of at least 150.degree. F and pressing the web to a pressure of at least 50 pounds per square inch, whereby the combination of heat, moisture, binder and pressure cause the second web to consolidate by activation of the adhesive or binder into a consolidated self-sustaining sheet of paper or paperboard,
• and means for combining the consolidated self-sustaining first web and the consolidated self-sustaining second web to form a multi-ply sheet of paper or paperboard.