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Foam Free Recirculating System for Magnetic Ink Jet Printer

IP.com Disclosure Number: IPCOM000084730D
Original Publication Date: 1975-Dec-01
Included in the Prior Art Database: 2005-Mar-02
Document File: 2 page(s) / 37K

Publishing Venue

IBM

Related People

Sambucetti, CJ: AUTHOR [+2]

Abstract

Magnetic inks have a strong tendency to foam due to their low-surface tension. In magnetic ink jet printers the foaming occurs in areas where air gets mixed with ink, for example, the gutter and return line. The ink is pumped from the gutter into a return vessel at a higher rate then it is delivered by the nozzle, since a level-sensing device is not feasible. This means that ink travels through the return line with enclosed air pockets which generate bubbles in the return vessel. This foaming can be eliminated completely by proper adjustment of the angle of impact of the ink stream such that no puddles can form.

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Foam Free Recirculating System for Magnetic Ink Jet Printer

Magnetic inks have a strong tendency to foam due to their low-surface tension. In magnetic ink jet printers the foaming occurs in areas where air gets mixed with ink, for example, the gutter and return line. The ink is pumped from the gutter into a return vessel at a higher rate then it is delivered by the nozzle, since a level-sensing device is not feasible. This means that ink travels through the return line with enclosed air pockets which generate bubbles in the return vessel. This foaming can be eliminated completely by proper adjustment of the angle of impact of the ink stream such that no puddles can form.

A trapping of air in the ink can be eliminated by making use of the property that ink is wetting most common materials which are used for printer construction. Fig. 1 is a top view of a gutter assembly 2, with Fig. 2 being a vertical section of Fig. 1 taken along the lines A-A.

An ink stream 4 from a source, not shown, impacts a glass plate 6 that is at an angle theta which for example, may be on the order of 20 degrees. This angle of impact eliminates the foaming at the point of impact as discussed above.

After the ink impacts the glass plate 6, the ink fans out and flows down the impactor surface to an oversized connection from the gutter to a return vessel 8. The droplets flow as a surface stream 10, with air escaping from the surface stream due to the low-surface tension of the ink on the wal...