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Stainless Steel Mesh Filter for Filtration of Magnetic Ink

IP.com Disclosure Number: IPCOM000081056D
Original Publication Date: 1974-Mar-01
Included in the Prior Art Database: 2005-Feb-27
Document File: 1 page(s) / 12K

Publishing Venue

IBM

Related People

Leslie, G: AUTHOR [+3]

Abstract

Systems requiring continuous filtration of ferro fluids such as magnetic ink jet printers have been shown to be greatly improved by the use of stainless steel filters. Significantly enhanced running time of filter and lowered pressure drops across the filters are the main advantages of stainless steel (SS) over other chemical-type membrane filters.

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Stainless Steel Mesh Filter for Filtration of Magnetic Ink

Systems requiring continuous filtration of ferro fluids such as magnetic ink jet printers have been shown to be greatly improved by the use of stainless steel filters. Significantly enhanced running time of filter and lowered pressure drops across the filters are the main advantages of stainless steel (SS) over other chemical-type membrane filters.

Since the ferro fluid consists of water insoluble magnetic material, other additives, such as fatty acid surfactants and water soluble glycols are incorporated to effect dispersion of the magnetic particles. One type of failure that has been observed is a partial dissolution of a polymeric filter (e.g., cellulose acetate) in a minor component of the aqueous ferro fluid (ethylene glycol) which results in greatly increasing the resistance of the filter to a point of ineffectiveness. Another disadvantage of the organic membrane filters containing polar carbonyl and other active sites which can enhance ordering of surfactant near the liquid/filter interface is the induced gelation and increased resistance. This failure is related to the high surfactant content and its tendency for short range ordering during quiescent periods. Still another type of problem with membrane filters, particularly the TEFLON* type which is known to be resistant to chemical attack, is the "wettability" of the filter by aqueous fluids. Experience has shown that a small fraction of the flui...