The Study On The Effect Of Agglomeration Deinking Of Offset Printing Waste Paper And Laser Printing Waste Paper

The utilization of secondary fiber has been increased tremendously during recent years. Ithas become an important source of fibers in papermaking due to the shortage of the forestresources. Office waste paper, which mainly consists of laser printed paper and xerographicpaper, is a fast growing source of secondary fiber due to the increase in the utilization of officephotocopiers and computer printers. People pay ore attentions on the deinking of the mix officewaste paper.The effect of the ink types and types of surfactants with different charge characteristicswere studied relative to the agglomeration of the laser toner ink under neutral pulpingconditions and alkaline pulping conditions. The paper also studied the effect of the alkaline onagglomeration of the mixed office waste papers. The results are as follow.The effect of agglomeration agent on agglomeration of different inks indicated:1. The inks and toners used on different papers have different compositions and differentcharacteristics, so the effects of the alkaline on separation between inks and fibers aredifferent. The alkaline is beneficial for the separation of the offset printed inks, andtakes no effect on separation of the laser toner ink.2. Agglomeration agent is a highly effective agglomerating agent for laser toner inkunder neutral pulping conditions. It can not make the offset printed inks agglomerate,but a small of it makes the ink separate from fibers easily.3. The optimal deinking conditions are different for different inks. The alkalineconditions are beneficial for the offset printed inks, and the best condition for lasertoner is the neutral conditions.4. The addition of a small amount of the offset ink printed waste paper is beneficial forimproving the agglomeration of laser toner ink. The optimal percentage of addition is12.5%to25%.The synergistic effect between surfactant and agglomeration agent is indicated:1. The effect of different surfactants on agglomeration of different types of inks isdifferent under the neutral pulping conditions. For laser toner ink, the cationicsurfactant not only reduced the NPM value but also enlarged the size of agglomeratedtoner ink. However, addition of SDBS and NP-10had a negative effect on the particlesize. For offset printed ink, three kinds of surfactants with different chargecharacteristics were all effective for NPM and gave positive results, and the nonionicsurfactant was the most effective one.2. Three types of surfactants showed positive effect on the agglomeration of mixed waste papers. But the optimum dosage of each surfactant was different. The effective is:cationic surfactant>anionic surfactant> nonionic surfactant.3. Addition cationic surfactant with agglomeration agent make the mixed inks underalkaline conditions, the average areas are enlarged.