Westvaco Corporation

Newpage Corporation

Dean R Johnson

Eric D Johnson

James E Shultz

Hans W Maurer

A coated paper product having high gloss and brightness is prepared by a process wherein a paper substrate is coated on at least one side with an aqueous coating formulation comprising an effective amount of a plastic pigment, and finished in a supercalender device containing heated rolls to produce a surface which is comparable to a cast coated surface.

High gloss coated paper

A method and apparatus are disclosed for uniformly applying a metered film of liquid to one or both surfaces of a web of paper, paperboard or the like at a waterbox calender to achieve enhanced finishing with minimal loss of caliper. For this purpose, a liquid metering element is adjustably mounted on a conventional waterbox associated with the calender, for precisely controlling the thickness and uniformity of a liquid film applied to the calender roll. The liquid film is subsequently transferred to the web at a transfer nip of the waterbox calender.

Waterbox calendering

The method comprises the application of a liquid film to a paper or paperboard rawstock web in a controlled and uniform manner to achieve a moisture gradient in the Z-direction thickness of the web to a depth of less than about one-half of the web thickness, and then pressing the treated web in at least one nip of a calender device before drying the web. The liquid application plasticizes only the surface fibers of the web so that the paper fibers at or near the surface become deformed and bonded under pressure to achieve a substantially irreversible smoothness upon being rewetted in a coating application or the like.

Growing community of inventors

Columbia, MD, United States of America

Dean R Johnson