Filter and method of making same
AssigneeAMF Incorporated
InventorsEugene A. Ostreicher, Kenneth C. Hou
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Abstract
A filter media sheet comprising fine particulate and a self-bonding matrix of cellulose fiber, the surfaces of at least one of which are modified with cationic colloidal silica.
Claims14
A filter media sheet consisting essentially of fine particulate and a self-bonding matrix of cellulose fiber, the surfaces of at least one of which are modified with a sufficient amount of an inorganic cationic colloidal silica to provide a positive zeta potential to the surface of the filter media sheet, wherein the cationic colloidal silica is derived from a dispersion of positively charged colloidal particles having a dense silica core modified with a polyvalent metal-oxygen compound wherein the polyvalent metal is aluminum, and a sufficient amount of the compound is provided to coat the silica to a level of at least 13% by weight of colloidal solids.
A method for the preparation of filter media sheets adapted for the removal of electronegative submicron contaminants from contaminated liquids comprising:
- felting a filter sheet from an aqueous slurry containing a composition consisting essentially of fine particulate and a cellulose pulp system as a self-bonding matrix, the surfaces of at least one of said particulate and said pulp being modified with a sufficient amount of an inorganic cationic colloidal silica to provide a positive zeta potential to the surface of the filter media sheet, wherein the cationic colloidal silica is derived from a dispersion of positively charged colloidal particles having a dense silica core modified with a polyvalent metal-oxygen compound wherein the polyvalent metal is aluminum, and a sufficient amount of the compound is provided to coat the silica to a level of at least 13% by weight of colloidal solids and drying said sheet.
Dependencies are inferred from the claim text.