| 摘要 |
<p>A process for removing waterborne flexographic inks from paper stock comprising the steps of: (a) forming a slurry by pulping paper containing waterborne flexographic inks in an aqueous medium having a pH of greater than 6 which includes: (1) one or more pH adjusting agents; (2) one or more nonionic surfactants; and (3) one or more anionic polyelectrolytes; and (b) subjecting the slurry produced in step (a) to a flotation cell including one or more cationic polymers is provided. The flotation cell can include one or more sources of calcium (2+) ions, magnesium (2+) ions, aluminum (2+) ions or aluminum (3+) ions. Examples of sources of materials which may be selected include the following materials: calcium chloride, aluminum chloride, magnesium chloride, calcium sulfate, magnesium sulfate or aluminum sulfate. In practice, when present, the source of positive ions is present in the flotation cell in amounts ranging from about 10 to about 1000 ppm, more preferably between about 300 and about 500 ppm.</p> |
