Date of Award
Bachelor of Science
Paper Science and Engineering
Surfactants are used in the deinking process for the dispersion of ink particles, collection of ink particles, and reduction of surface tension. Surfactant characteristics are vital in understanding the efficiency of a surfactant on ink particles. Evaluation on the efficiency of surfactants and on toner particles is critical to optimize a deinking process and improve selection of deinking surfactant candidates.
By deinking xerographic inks with series of nonionic, anionic, and cationic surfactants, the efficiency was reported. By using the HLB (hydrophile-lipophile balance) empirical method of rating surfactants, the efficiency was correlated to structure and other surfactant properties. Normally when the HLB value of a surfactant is high, the hydrophilic nature of the surfactant is high as is the polarity. Also, by contrast, when a surfactant has a low HLB value, it tends to have a higher hydrophobic nature and a more nonpolar characteristic. These values are based on the number of hydrophilic groups on the surfactant primary structure. Thus, by applying these concepts to the process of deinking, this report revealed the efficiency of cationic, anionic, and nonionic surfactants through the results of image analysis and ink removal efficiency.
Overall, the nonionic and cationic surfactants had the best ink removal efficiency. Anionic surfactants showed poor results. For the nonionic and cationic, an increase in ink removal efficiency correlated to a net increase in HLB. An increase in surfactant concentration increased ink removal efficiency for the nonionic and cationic surfactants. Alkaline conditions showed better results for the nonionic than cationic.
McLaughlin, Andrew, "The Efficiency of Surfactants on Xerographic Ink" (1997). Paper Engineering Senior Theses. 299.