Feasibility of Utilizing Corn Stalk Residues in Chemi-Mechanical Pulping (CMP) and Papermaking

The influence of pulping conditions on properties of CMP pulp from corn stalks is investigated.Pulps were prepared from undepithed and depithed corn stalks, utilizing different pulping variables. Presence of pith lowered both yield and strength. Therefore different pulping conditions using sodium sulfite and sodium hydroxide were selected and applied ondepithed corn stalks. Sodium sulfite charge varied between 8-14% and sodium hydroxide charge was kept constant at 8%. Pulping time varied at 30, 45, and 60 minutes. Total yieldsafter impregnation were measured between the minimum of70.8% and minimum of 87.2%.However, the yield after defibration was lower than the above mentioned values and variedbetween 53.1% and 68.7%. Based on the measured yields, different sodium sulfite chargesat constant amount of the sodium hydroxide, time, and temperature were selected for pulpstrength evaluation. The results of hand sheet evaluation revealed that the strength of thepulp produced using 10% Na2S20 3, 8% NaOH, during 30 minutes time and at 95°C with abreaking length of 1.98 km, 8.28 mN.m2/g tear index and 20.40 N.m/g tensile index was superior to that obtaind under other pulping conditions.