The use of surfactants in de-inking paper for paper recycling

Pulp and Paper Chemicals∗∗Some excerpts taken from Bajpai, P., 2004. Emerging Technologies in Sizing. PIRA Technology Report, Smithers PIRA, the worldwide authority on the Packaging, Print and Paper supply chains.

“…Other chemicals such as polysulfides and surfactants are also becoming strong candidates to be considered as pulping additives during kraft pulping (Borchardt, 1997;Borchardt et al, 1997;Bajpai et al, 2005). An ideal alternative process to achieve extended delignification should be one with less extensive and/or expensive modifications.…”

“…A number of surfactants have been reported which improve flotation deinking (Borchardt, 1997). Surfactants used in flotation deinking cannot work in the way that surfactants probably work in wash deinking (Seifert and Gilkey, 1997).…”

Chemicals Used in Deinking and Their Function

“…The role that sodium silicate plays in a newsprint deinking system has been studied by several workers (Ali, McLellan, Adiwinata, May, & Evans, 1994;Borchardt, 1995Borchardt, , 1997Ferguson 1991Ferguson , 1992aMahagaonkar, Banham, & Stack, 1996, 1997Mathur, 1991;McCormick, 1990McCormick, , 1991Pauck & Marsh, 2002;Read, 1986Read, , 1991Renders, Chauveheid, & Dionne, 1996;Santos, Carre, & Roring, 1996). It is apparent that sodium silicate's role seems to be multi-faceted, and can be summarised as follows: its main function is to stabilise the hydrogen peroxide used to bleach the pulp in the pulper.…”

Surfactants Based on Natural Fatty Acids

“…The ability of fatty acid soaps to adsorb selectively to solid particles in aqueous solution is used in many applications, for example lubrication [22], flotation de-inking of paper [23] and purification of minerals [24]. The surface chemical aspects of the process of de-inking has been reviewed by Theander and Pugh [25].…”