The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Apr. 09, 1996
Filed:
Jan. 11, 1995
Douglas W Donigian, Baltimore, MD (US);
Suzanne S Fenton, Tolland, CT (US);
Bryan J Ortman, Beaumont, TX (US);
Hiawatha P Watkins, Columbia, MD (US);
Westvaco Corporation, New York, NY (US);
Abstract
A paper rawstock web is wet densified on a papermachine at a moisture content greater than about 20% and less than about 50%, and preferably from about 25-35%, in a calender device at nip pressures greater than about 3000 psi, and preferably within the range of from about 3000-6000 psi, to provide fiber springback resistance and irreversibly smooth surfaces which are substantially resistant to loss of smoothness upon rewetting, as for example in a subsequent surface sizing or coating process. Wet densification according to the present invention produces a web having greater density and increased internal bond strength, as compared with webs treated by conventionally known methods, to achieve the irreversibly smooth surfaces.