Microcrystalline cellulose: an alternative to increase the resistance of kraft packaging with recycled fiber

Abstract

The consumption of paper packaging is increasing. On the contrary, the planted areas of Pinus spp. are showing a trend tendency of imbalance between supply and demand. Therefore, many companies are prioritizing the use of recycled fiber (RF). However, its inclusion can influence the quality of the product. This study aimed to evaluate whether the combination of RF with microscale cellulose will enable the production of resistant paper. The first step involved producing bench-scale samples of Kraft paper (with different percentages of virgin and RF) and characterized it physically (grammage, moisture, Gurley porosity, Z-traction, SCT, and Mullen). The second stage involved replicating the first stage with the inclusion of microcrystalline cellulose (MCC) and the elimination of Pinus spp. (LF). All formulations were approved for the physical characterization tests, except for the porosity analysis and grammage for F5. In the first test (MCC=0%), there was a reduction in tensile, compression, and burst index of 13.2, 7.3, and 19.5%, respectively, showing that the higher the percentage of RF, the lower the paper’s strength. In the second test for Formulation 3 (MCC=6%), there was an increase in the tensile, compression, and burst index of 9.5, 2.6, and 2.7%, respectively, when compared with Formulation 2 (LF=MCC=0%). This study demonstrates that the addition of up to 6% MCC strengthens the RFs and decreases the dependence on Pinus spp., making it a promising alternative for the production of sustainable and resistant packaging.