Patents by Inventor Douglas W. Donigian

Douglas W. Donigian has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).

  • Patent number: 5505820
    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.
    Type: Grant
    Filed: January 11, 1995
    Date of Patent: April 9, 1996
    Assignee: Westvaco Corporation
    Inventors: Douglas W. Donigian, Suzanne S. Fenton, Bryan J. Ortman, Hiawatha P. Watkins