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Jet Printer Ink Supply System

IP.com Disclosure Number: IPCOM000079638D
Original Publication Date: 1973-Aug-01
Included in the Prior Art Database: 2005-Feb-26
Document File: 3 page(s) / 45K

Publishing Venue

IBM

Related People

Findlay, HT: AUTHOR

Abstract

Nonuniformity of colloidal and Newtonian inks as a result of flocculation and settling, interferes with the flow properties of these inks in magnetic and electrostatic ink jet systems. Studies of flocculation and settling in colloidal magnetite aqueous systems (ferromagnetic fluids) indicate that many jet ink flow problems experienced with ferrofluids, as well as solution systems, are directly related to flocculation, settling and phase separation. Studies show that flocs and gel particles formed as a result of evaporation, or as a result of static conditions in colloidal inks, are not deflocked by the normal ink withdrawal stream in the ink jet system. The need for ink filtering immediately before using as well as start up blocking problems, are indications that a serious potential and a real problem exists.

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Jet Printer Ink Supply System

Nonuniformity of colloidal and Newtonian inks as a result of flocculation and settling, interferes with the flow properties of these inks in magnetic and electrostatic ink jet systems. Studies of flocculation and settling in colloidal magnetite aqueous systems (ferromagnetic fluids) indicate that many jet ink flow problems experienced with ferrofluids, as well as solution systems, are directly related to flocculation, settling and phase separation. Studies show that flocs and gel particles formed as a result of evaporation, or as a result of static conditions in colloidal inks, are not deflocked by the normal ink withdrawal stream in the ink jet system. The need for ink filtering immediately before using as well as start up blocking problems, are indications that a serious potential and a real problem exists. The following serves to illustrate the extent of the condition.

Fifty-five ml of colloidal magnetite is placed in a cylinder to form a vertical column 39 cms long. The base is sealed with a permeable rubber stopper. At regular time intervals, a weighed amount of 0.01 ml of sample is withdrawn from the base of the column by a hypodermic needle. The information obtained is plotted time vs. weight of sediment. The jet ink flow and drop formation system is designed for a uniform stable ink system. Settling causes plugging of the filter, loss of pressure, increase in viscosity, and erratic or complete loss of drop formation. Consistency of ink properties is essential and can be obtained by the device illustrated.

The device consists of a flexible polyethylene sac filled with ink, and air is excluded. Inks that are improved are those that have innate sedimentation properties, or exhibit progressive phase separation and sedimentation, as a result of time, temperature change, or chemical reaction. Sealed to one end of the sac, there is attached a solid-plastic ring that may or may not enclose a filter. Recessed on the outside of the ring frame, and continuous with the ring frame, there is a raised section that consists of an elastic and puncturable outer wall. The puncturable outer wall is so designed as to be penetrated by a sharp metallic ink effluent pipe.

Emissions of ink from the sac to the outlet pipe is against the pull of gravity. At the base of the sac there is contained a small amount of hollow glass rods, to allow for accumulation and retention of heavy granular or flocked or gelled material that is not readily resuspended in the continuous phase.

Heavy material in the ink settles to the bottom of the sac and is held in the recess of the hollow rods. The sac is filled with ink and air e...