Method for producing corrugated cardboard

Abstract

A method is provided for applying adhesive to the flutes of a corrugated sheet to bond a face surface thereto. An applicator roll is provided with a uniform thin coating of adhesive by a metering rod urged toward the surface of the applicator roll. A rider roll is provided adjacent the applicator roll and at the same height to form a vertical space for passage of the corrugated sheet therebetween so that the amount of glue applied to the crests of the flutes is proportional to the speed of the applicator roll. The space between the applicator roll and the rider roll is precisely controlled to control the degree of compression of the flutes during the application of the adhesive thereto. The flutes are preferably compressed 3-30, preferably 5-15, percent of their initial height to prevent application of adhesive to the rear sloping faces of the flutes. The applicator roll has a surface linear velocity substantially less than the speed of the corrugated sheet to accurately control the amount and placement of adhesive applied to the flutes.

Dependencies are inferred from the claim text.