Development of Deinking Agents for Flotation Systems, 1994 Recycling Symposium Proceedings

Kohji Masamizu, Yuji Tai, Masaaki Hagiwara, Toshiyuki Ukigai

Following the recent worldwide demand for high-quality recycled pulp, the technology for deinking equipment and deinking agents has made remarkable progress. Particularly, there is a great demand for new, efficient deinking agents designed for state of the art equipment coming into use by various paper manufacturers.

In response to this demand, a laboratory evaluation method was developed to measure deinking agent efficiency. By introducing the concepts of ink removal energy in the pulping process, agitation Reynolds number and gas-liquid ratio in the flotation process, a method capable of providing experimental conditions suitable to represent actual mill systems was achieved. Using this evaluation method, new deinking agents were developed having excellent ink removal and ink collection efficiency and rapid foam collapse after flotation. By utilizing the developed evaluation method and controlling the addition of alkyleneoxide to a high alcohol, the above-mentioned properties can be fitted to individual mill systems. Newly developed high-alcohol-type EOPO copolymers (single-chain type) are compared to fatty acid and oil & fat type EOPO copopolymers (double-chain type) using the described laboratory method.