Mitsuo Ozaki

Fixing Time Of Ink-Jet Inks On Plain Paper

We investigated water-based ink-jet inks which fix quickly on plain paper. Ink-jet inks have liquid components which evaporate slowly to prevent the print head nozzles from clogging. The fixing time of these inks is too long for printing on plain paper. Inks cannot penetrate paper which contains a sizing agent, which increases the papers resistance to liquids. The most widely used sizing agent is rosin. We attempted to shorten fixing time by including in the ink, a component for dissolving rosin. The glycols used in the ink are useful because they evaporate slowly. We determined the relationship between the solubility of the ink for sizing agents, rosin, and the time needed for fixing and penetration. The higher the solubility of a glycol for rosin, the faster the penetration of the ink containing it. Hexylene glycol dissolves rosin over 70 wt%, and ink containing over 15 wt% hexylene glycol penetrated plain paper within 5 seconds.

Electrostatic screen-through ink jet printing technique

The authors designed an electrostatic ink jet printing technique that prints using a voltage lower than conventional techniques. The assembly consists of a closely aligned ink roller, mask screen, paper, and an electrode. A voltage pulse is applied between the ink and electrode, then electrostatic force overcomes the surface tension of the ink, and the ink goes through holes in the screen and sticks to the paper. Major factors affecting the success of this technique are the materials comprising the screen, ink attributes, and electrostatic force.