PULPING OF CORN STALKS - ASSESSMENT FOR BIO-BASED PACKAGING MATERIALS

Agricultural residues resulting as side-streams from harvesting cereals have lately gained particular interest for pulping and papermaking due to their availability and low price. Corn (Zea mays) is one of the most important cereals and its harvesting yields amounts of stalks in the range of 1.7-4.5 t/ha. In the present paper, the chemical composition of corn stalks was determined and the obtained values represent an argument for their use as feedstock for papermaking fiber production. Furthermore, alkaline pulping processes using different cooking agents were tested for conversion of corn stalks to papermaking pulp. The obtained pulps were characterized with respect to yield, Kappa number and viscosity, and were then subjected to beating and handsheet formation. The mechanical properties (tensile and bursting strength, corrugating medium flat crush resistance and short span compressive strength) of the handsheets obtained with different beating degrees were determined in order to find out the optimum cooking and/or refining conditions and the most suitable cooking agents to obtain pulps with good papermaking properties. The findings of this study provide insights into new opportunities to utilize a low-cost raw material to produce high-value bio-based materials, resulting in significant savings for the pulp and paper industry.