Physical and Mechanical Properties of Papers Produced From Different Cellulosic Pulps Blending

Abstract

AbstractThis study aimed to evaluate the effect of different fiber blending in the physical-mechanical properties of papers and understand to what extent the fiber blending influence produced paper quality. Three different commercial cellulosic pulps were used: eucalyptus, sisal, and pine pulp. Fiber morphological analyses were performed after refining in each pulp. The pulps were blended two by two in 5/95%, 25/75%, and 45/55% ratio in all possible combinations. Handsheets were formed (2% consistency) in a lab papermaking machine and tested by physical and mechanical properties. Virgin pulps (without blending) were also used for handsheet production. Fibers presented different features regarded to morphological properties and indexes. Most significant differences were related to fiber length. Statistical differences occurred in all physical and mechanical properties. Differences were due to morphological features. The highest and lowest values were pointed out for each property. Thickness tended to decrease with fiber blending in all proportion. Thickness and grammage were not related. For all mechanical properties, the lowest values were obtained in eucalyptus treatment and blending involving it. The highest values were obtained in pine, sisal, and blending treatments. A small addition of sisal (5%) in eucalyptus pulp improved the tensile strength, tensile index, stretch, bursting index, tear index, and fold endurance in approximately 41.5, 54.8, 51.4, 28.9, 37.5, and 33.3%, respectively. The same addition using pine resulted in an improvement of 15.9, 22.7, 22.7, 37.4, 46.7, and 133.3%. Fiber blending presented a synergetic effect for physical and mechanical properties.