The Design Of New Deinking Agent And Study On The Deinking Mechanism

The resource to make paper is shrinking increasingly and the environmental protection becomes more and more important, therefore the recycling of waste paper has received more attentions in the paper industry. The recycled fibers have become an important resource in paper making. In order to improve the quality of recycled fibers, the surfactants play a key role in the de-inking process. In this paper, a series of polyether (SEP) was synthesized for use in the de-inking process. Our objective is to study the mechanism of surfactant to provide some reference of de-inking process.In this paper, the SEP with different molecular structures were evaluated as the de-inking agent. The relationship between the wetting and emulsification capability of nonionic surfactant and the de-inking efficiency were reviewed. In the meantime, important properties of surfactant, such as surface tension, contact angle, and adhesion, are discussed in the context of de-inking. Furthermore, the combination of polyether (SEP) with other surfactants under neutral condition was investigated in this paper.In the study, we have found that the SEP performs well for both old news paper and mixed office wastepaper. It can increase of brightness reaches to about 9% and 6%.The structure of polyether such as molecular weight and HLB have obvious effect on the de-inking efficiency. And the surface property of polyether plays the primary role. Based on these discoveries, we have developed a new procedure to choose the suitable surfactant. Our procedure brings significant savings in experimentation for the study of new de-inking agents.In the neutral de-inking process, we find the combination of surfactants can greatly improve the de-inking efficiency. In comparison with traditional alkaline de-inking, we find neutral de-inking can perform better;it increases the brightness over 6% and poses no environmental hazard.