THE INFLUENCE OF SURFACTANT UNDER NEUTRAL REPULPING CONDITION ON DE-INKING EFFECT OF WATER-BASED INK

摘要

The influence of surfactant, repulping time and temperature under neutral condition (without NaOH) on de-inking effect of water-based ink was discussed in this paper. Results showed that the best repulping process under neutral condition was as follows, temperature was 50°C, speed of repulper was 150r/min, repulping time was 25mins and repulping concentration was 20%. Under these conditions the research on surfactant was investigated. Results indicated that the de-inking effect with cationic surfactant alone was better than that with anionic surfactant and non-ionic surfactant. Moreover the best dosage of cationic surfactant was 0.6%. In addition the de-inking effect with anionic surfactant was better than that with non-ionic surfactant. The whiteness was increased by 7~9%ISO with non-ionic surfactant and anionic surfactant. However the whiteness was just increased by 3~5%ISO with non-ionic surfactant and cationic surfactant. When the dosage of sodium silicate was 3% and surfactant was used at the same time, and the whiteness can be increased by 2~6%ISO.