Patents Assigned to Institute of Paper Science & Technology
  • Patent number: 6492174
    Abstract: The present invention provides methods for initiating embryogenic cultures of plants. The methods include the use of novel media compositions and elevated atmospheric pressure treatments to improve the frequency of embryogenic culture initiation. The methods are well suited for initiating embryogenic cultures in recalcitrant conifer varieties. The method is also well suited for producing somatic embryos that can be further cultured to produce large numbers of plants. Further, the invention provides novel methods that may be used to enhance somatic embryogenesis in a broad range of species.
    Type: Grant
    Filed: October 11, 2000
    Date of Patent: December 10, 2002
    Assignee: Institute of Paper Science & Technology
    Inventors: Gerald S. Pullman, Gary Peter
  • Patent number: 5803270
    Abstract: Methods and apparatus for acoustic fiber fractionation using a plane ultrasonic wave field interacting with water suspended fibers circulating in a channel flow using acoustic radiation forces to separate fibers into two or more fractions based on fiber radius, with applications of the separation concept in the pulp and paper industry. The continuous process relies on the use of a wall-mounted, rectangular cross-section piezoelectric ceramic transducer to selectively deflect flowing fibers as they penetrate the ultrasonic field. The described embodiment uses a transducer frequency of approximately 150 kHz. Depending upon the amount of dissolved gas in water, separation is obtained using a standing or a traveling wave field.
    Type: Grant
    Filed: October 31, 1995
    Date of Patent: September 8, 1998
    Assignee: Institute of Paper Science & Technology, Inc.
    Inventor: Pierre Brodeur
  • Patent number: 5792321
    Abstract: Methods and apparatus to enhance paper and board forming qualities with insert tubes and/or a diffuser block in the paper forming machine headbox component which generates vorticity in the machine direction (MD) which is superimposed on the streamwise flow to generate a swirling or helical flow through the tubes of the diffuser block. Tubes of the diffuser block are designed such that the direction of the swirl or fluid rotation of the paper fiber stock may be controlled and the direction thereof is controlled in such a way to provide effective mixing, coalescence and merging of the jets of fluid emanating from the tubes into the converging section, i.e., nozzle chamber of the headbox. Also disclosed is the effective mixing of the jets generating cross-machine direction (CD) shear between the rows of jets that form at the outlet of the tubes inside the nozzle chamber of the headbox to align paper fibers in the cross-machine direction, thus increasing CD strength of the manufactured sheet.
    Type: Grant
    Filed: October 20, 1995
    Date of Patent: August 11, 1998
    Assignee: Institute of Paper Science & Technology, Inc.
    Inventor: Cyrus K. Aidun
  • Patent number: 5101574
    Abstract: The present invention is directed to a method and apparatus for drying a web of paper utilizing impulse drying techniques. In the method of the invention for drying a paper web, the paper web is transported through a pair of rolls wherein at least one of the rolls has been heated to an elevated temperature. The heated roll is provided with a surface having a low thermal diffusivity of less than about 1.times.10.sup.-6 m.sup.2 /s. The surface material of the roll is preferably prepared from a material selected from the group consisting of ceramics, polymers, glass, inorganic plastics, composite materials and cermets. The heated roll may be constructed entirely from the material having a low thermal diffusivity or the roll may be formed from metal, such as steel or aluminum, or other suitable material which is provided with a surface layer of a material having a low thermal diffusivity.
    Type: Grant
    Filed: October 15, 1989
    Date of Patent: April 7, 1992
    Assignee: Institute of Paper, Science & Technology, Inc.
    Inventors: David I. Orloff, Gerald R. Kloth, Gary R. Rudemiller