The Potential of Nanosilica – Cationic Starch Wet End System for Applying Higher Filler Content in Fine Paper

Abstract

Multiple studies have considered the nanosilica-cationic starch system to be a retention/drainage aid; however its potential to improve strength has previously been neglected. This research focused on the effect of both nanosilica and cationic starch on certain crucial physical and mechanical properties of fine paper compared with a paper sheet containing no additives to evaluate how this system can compensate for using more filler in fine paper. In previous studies, it was suggested that the cationic starch-nanosilica system induces much tinier flocs and thus possibly results in better strength properties. In this respect, results revealed that cationic starch did, however, improve tensile index; this effect weakened at higher filler levels. Cationic starch and nanoparticles both improved internal bonding, while cationic starches' effect was more prominent. With more filler, tear index suffered. Although addition of cationic starch partly compensated this negative effect with filled papers, nanoparticles did not seem to have an obvious effect. Therefore, cationic starch provided the limited potential of using more filler and nanoparticles may do it indirectly.

Effects of cationic starch addition and pulp beating on strength properties of softwood kraft pulp

“…The addition of CS to unbeaten pulp (15°SR) in all three ratios (0.75, 1.5, and 2.25%) resulted in tensile index increases of 59, 64, and 70%, respectively. The positive effect of CS on the tensile index has been previously reported [7,13]. These increments could be explained by the significant increases in the relative bonded area (RBA) with increasing CS addition [10].…”

“…With additions higher than 2%, added CS will remain in the solution phase without being adsorbed by the fibers [9]. The strength-enhancing effects of CS have been reported in previously published studies [7,[10][11][12][13][14][15][16].…”

Prospects for Maintaining Strength of Paper and Paperboard Products While Using Less Forest Resources: A Review

“…In particular, sequential addition of cationic starch and colloidal silica products, i.e. nanoparticles, can provide a combination of dry-strength improvement and increased dewatering (Swerin et al 1995;Hubbe 2005b;Khosravani and Rahmaninia 2013).…”

“…For that reason, microparticle systems can be viewed not only as a strategy to optimize retention and dewatering, but also as a way to more effectively retain a dry-strength additive, such as cationic starch. Indeed, various studies have shown that combinations of cationic starch and colloidal silica can be beneficial for increasing paper's dry-strength properties (Moberg 1985(Moberg , 1986Nilsson and Carlson 1993;Sunley 1997;Khosravani and Rahmaninia 2013).…”

Biobased polymers and cationic microfibrillated cellulose as retention and drainage aids in papermaking: Comparison between softwood and bagasse pulps

“…The use of anionic microparticles in conjunction with a cationic polymer offers an interesting alternative: these retention aids yield a better balance between sheet formation and retention than the traditional retention systems (Wägberg and Lindström, 1987;Cho et al, 2006). The major difference between these systems relies on the kind of microparticle used, such as anionic colloidal silica, bentonite, colloidal aluminium hydroxide and micropolymers (Andersson et al, 1986;Lindström et al, 1989;Andersson and Lindgren, 1996;Swerin et al, 1993;Swerin and Ödberg, 1996;Honig et al, 1993Honig et al, , 2000Khosravani and Rhamaninia, 2013). System based on the use of colloidal silica is considered as the most effective but its price is high and this is the main reason for the increasing use of bentonites which are less expensive.…”