Abstract: Mixed office waste paper(MOW) were deinked under neutral condition to investigate the relationship between deinking effect and foamability of deinking agents.The result showed that, among single-component deinking agents, the deinking effect becomes worse with the increased foamability of anionic surfactants and the effect becomes better with the increased foam stability of surfactant. Brightness of deinked pulp treated by the best foamability surfactant AEC-7-Na is only 80.51%(ISO), while brightness of that treated by the best foam stability surfactant ABS is 83.04%(ISO). For nonionic surfactants, there is no obvious relationship between deinking effect and foamability,also foam stability has no effect on deinking effect. It is proofed in the experiment of blended nonionic and anionic surfactants, that the relationship between deinking effect and foamability is uncertain. The main factors which decide the deinking effect are the collecting ability of nonionic surfactants and the blendability of two kinds of surfactants. In this experiment, several blended groups of neutral deinking combination with outstanding deinking effect,such as(the mass ratio 1:1): T-80+SAS, AEO20+AES, AEO12+AEC-7-Na, S-80+AES, have been obtained.

Key words: neutral deinking agents, mixed office wastepaper, foamability, deinking effect, surfactant