New Diatomite Filler for Improvement of Paper Strength Properties

Abstract

In this work, diatomite particles were modified to improve the bondability of diatomite particles with pulp fibers and filler retention via a complex of cationic starch-sodium hexametaphosphate coating method. The particle size, FTIR spectroscopy characteristic and morphology of the resulting modified diatomite were studied to confirm the successful modification. The SEM results illustrated that the surface of modified diatomite particles was covered by the complex coatings. The coating efficiency of the complex of cationic starch-sodium hexametaphosphate on diatomite surface was up to 98%. Compared with the handsheet filled unmodified diatomite, the handsheet filled with modified diatomite had higher strength properties and lower bulk. When cationic starch dosage was 7%, and filler dosage was 25% , the resulting tensile strength of filled modified diatomite handsheet was 22.1% higher than the handsheet filled unmodified diatomite. Furthermore, with the filler loading of 30%, compared with that of unmodified diatomite, filler retention of modified diatomite was increased by 20.4%. The larger particle size and higher zeta potential of modified diatomite were benefitial to increase retention of modified diatomite filler.

Investigation of the Adsorption Behavior of Jet-Cooked Cationic Starches on Pulp Fibers

“…In the paper industry, usually low DS starches ranging from 0.02 to 0.1 are employed. These serve as an adsorbate on the negatively charged cellulose fibers, improve the fixation of other additives [ 16 , 17 ], increase strength, improve abrasion resistance, and contribute to maintain dimensional stability [ 18 ]. The efficiency of cationic starches as strength enhancing agents is correlated with the amount adsorbed onto cellulosic fibers [ 19 , 20 ].…”