Patents by Inventor Jawed M. Sarkar

Jawed M. Sarkar 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: 5507914
    Abstract: A process for enhancing the freeness of paper pulp, which comprises the steps of adding to the pulp from about 0.5 to about 2.5 kilograms per ton based on the dry weight of the pulp, of a cellulolytic enzyme at the vertical tank of the papermaking process, allowing the pulp to contact the cellulolytic enzyme for from about 30 minutes to about 60 minutes, adding at least 0.011%, based on the dry weight of the pulp, of a water soluble cationic polymer, adding at least 0.007%, based on the dry weight of the pulp, of a water soluble anionic polymer and forming the thus treated pulp into paper.
    Type: Grant
    Filed: June 7, 1995
    Date of Patent: April 16, 1996
    Assignee: Nalco Chemical Company
    Inventors: Jawed M. Sarkar, Hanuman P. Didwania
  • Patent number: 5501770
    Abstract: A process for improving the freeness of paper pulp, which comprises the steps of adding to the pulp at least 0.05%, based on the dry weight of the pulp, of a cellulolytic enzyme, allowing the pulp to contact the cellulolytic enzyme for from about 40 minutes to about 60 minutes at a temperature of at least 40.degree. C., adding at least 0.011%, based on the dry weight of the pulp, of a water soluble cationic polymer, adding at least 0.007%, based on the dry weight of the pulp, of a water soluble anionic or nonionic polymer and forming the thus treated pulp into paper.
    Type: Grant
    Filed: August 12, 1994
    Date of Patent: March 26, 1996
    Assignee: Nalco Chemical Company
    Inventors: Jawed M. Sarkar, Hanuman P. Didwania
  • Patent number: 5423946
    Abstract: A process for improving the freeness of paper pulp, which comprises the steps of adding to the pulp at least 0.05%, based on the dry weight of the pulp, of a cellulolytic enzyme, allowing the pulp to contact the cellulolytic enzyme for from about 40 minutes to about 60 minutes at a temperature of at least 40.degree. C., adding at least 0.011%, based on the dry weight of the pulp, of a water soluble cationic polymer, adding at least 0.007%, based on the dry weight of the pulp, of a water soluble anionic or nonionic polymer and forming the thus treated pulp into paper.
    Type: Grant
    Filed: March 7, 1994
    Date of Patent: June 13, 1995
    Assignee: Nalco Chemical Company
    Inventors: Jawed M. Sarkar, David R. Cosper
  • Patent number: 5326479
    Abstract: A process for removing color from a pulp and paper wastewater which comprises the following steps: (a) treating the wastewater with a reducing agent which is capable of inactivating color producing functional groups of the wastewater; and (b) treating the wastewater subsequent to step (a) with a polymer which is capable of removing color from the wastewater.
    Type: Grant
    Filed: September 1, 1993
    Date of Patent: July 5, 1994
    Assignee: Nalco Chemical Company
    Inventors: Jawed M. Sarkar, Amy M. Tseng, John H. Collins
  • Patent number: 5256252
    Abstract: A method of controlling pitch deposits in a pulp and papermaking process comprising adding lipase and a cationic polymer to a cellulosic slurry in amounts effective for diminishing pitch deposits from the cellulosic slurry in a pulp and/or paper mill. The method may include adding lipase and a cationic polymer to a cellulosic slurry in amounts effective for both reducing the triglyceride content of a cellulosic slurry by hydrolysis and diminishing the concentration of fatty acids released by the hydrolysis in the aqueous phase of a cellulosic slurry. The triglyceride hydrolysate content of the aqueous phase of a cellulosic slurry, formed by the action of lipase on triglyceride within the cellulosic slurry, is reduced when the amount of lipase and the amount of a cationic polymer is maintained for a time period sufficient to hydrolyze at least some of the triglyceride in the cellulosic slurry and reduce the triglyceride hydrolysate in the aqueous phase of the cellulosic slurry.
    Type: Grant
    Filed: July 15, 1992
    Date of Patent: October 26, 1993
    Assignee: Nalco Chemical Company
    Inventors: Jawed M. Sarkar, Martha R. Finck
  • Patent number: 5169497
    Abstract: A process for improving freeness of paper pulp which comprises these steps:a) Adding to the pulp at least 0.05% based on the dry weight of the pulp, of a cellulolytic enzyme;b) Allowing the pulp to contact the cellulolytic enzyme for at least 20 minutes at a temperature of at least 20.degree. C.;c) Adding at least 0.0007% based on the dry weight of the pulp of a water soluble cationic polymer, and thend) Forming the thus treated pulp into paper.
    Type: Grant
    Filed: October 7, 1991
    Date of Patent: December 8, 1992
    Assignee: Nalco Chemical Company
    Inventors: Jawed M. Sarkar, David R. Cosper