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US 5,225,041 AGranted
Refining process for paper pulp using a silica sol
AssigneeSociete Francaise Hoechst
InventorsMichel Richard, Christian Roux, Claude Trouve
Life of this patent
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Abstract
A refining process for paper pulp in which colloidal silica sol is mixed with the paper pulp to be refined. The addition of the colloidal silica sol reduces the time necessary to refine the pulp to a predetermined freeness value compared to refining in the absence of the colloidal silica sol.
Claims3
A process for refining paper pulp consisting essentially of
- adding to said paper pulp a colloidal silica sol in an amount effective to reduce the time necessary to refine said paper pulp to a predetermined freeness value compared to refining in the absence of said colloidal silica sol, said amount comprising 1-50% by weight of said silica sol, on a dry basis, relative to the weight of said paper pulp on a dry basis, and
- refining said paper pulp in the presence of said colloidal silica sol to said predetermined freeness value.
Dependencies are inferred from the claim text.