EFFECT OF CELLULOSE MICROFIBERS ON PAPER WITH HIGH CONTENTS OF RECYCLED FIBER

Abstract

The papers that are produced with recycled fiber material loose structural properties or have quality differences with respect to similar products made from virgin fiber, which is attributed to the low binding capacity between fibers and their potential to decrease water absorption, which favors the reduction of flexibility for hardening of the outer layers of the fiber, and that, in turn, reduces the ability of binding, and the formation of hydrogen bonds; this adversely affects the strength properties of paper structure. In this experiment, Cellulose Microfibers (MFC) were added to the formulation of Kraft paper of virgin fiber mixture and recycled fiber (20-/ 80 %, respectively) in order to increase their resistance properties. MFC generation was performed by oxidation of Eucalyptus camaldulensis fiber and treated with NaIO4 NaClO2 and mechanically released. The MFC was added at concentrations of 2.5, 5.0, 7.5 and 10.0 % by weight dry basis; cationic starch (0.8 and 1.6 % w bs) was used as retention agent and sodium silicate as a mordant agent; and as response variables, the porosity of the paper produced and tensile strength were assessed, which when 10% MFC was added, it increased by 36.8 %.