Application Of Waste Corn Stalks Materials In Pulp And Papermaking Fields

Corn stalks as raw materials for the production of chemical pulp and bio-pretreatment chemomechanical pulping have been introduced in the paper. What is more important is, application of core of corn stalks in pulp and paper fields was studied primarily.The corn stalk is one kinds of important plant fiber material, the content of cellulose is higher and the content of lignin is lower in straw epidermis than wheat straw. So corn straw epidermis has already applied in the papermaking industry as a important raw fiber materials. In same cooking conditions, pulp yield of corn straw epidermis NaOH-AQ pulp and Kappar numbe are higher than wheat straw NaOH-AQ pulp. Two pulps made with NaOH-AQ pulping methods were bleached by three stage bleaching of general CEH. Bleaching result shows that corn straw epidermis pulp consumes more slightly chemical bleaching agent than wheat straw pulp. Strength properties of corn straw epidermis pulp are less than wheat straw pulp's relatively. But strength properties of corn straw epidermis pulp were further improved when pulp contained some modified core of corn stalks.Core of corn stalks was modified in a appropriate treatment process and then mixed with poplar APMP, wheat straw pulp and bio-pretreatment chemomechanical pulp of corn straw epidermis. Opacity of three mixed pulps is lower than that of control. As for colour reversion value, poplar APMP and bio-pretreatment chemomechanical pulp of corn straw epidermis is decline and wheat straw pulp is increased. Strength performance analysis shows that modified core of corn stalks can improved strength properties of beated pulp and unbeated pulp, but improvements of unbeated pulp is more obvious. Such as, tensile strength, tear strength and burst strength increased 25.14%, 2.39% and 18.96% respectively when the content of core of corn stalks is 40% in beated APMP. Meanwhile, corrugated boards were made from corn stalks and were analyzed. The results show that tensile strength and crush strength increased 58.11%, and 91.82% corresponding to he content of core of corn stalks is 30%.Mechanism about modified core of corn stalks improve pulp strength performance have been studied by SEM and FTIR spectrograms. SEM shows that modified core of corn stalks can into the gap among fibers, the fibers bonded together and reinforced fiber bonding. FTIR spectrograms analysis shows that the hemicelluloses in core of corn stalks were oxidized and some functional groups, such as–OH become–COOH or–CHO. These groups can reinforce fiber bonding and improve paper's strength performance. Clearly, hemicelluloses play an important role in this mechanism.A preliminary study about effect of hemicelluloses on pulp properties was carried out. A part of hemicelluloses have been removed from poplar wood Alkaline Peroxide Mechanical Pulping by xylanase treatment. The contents of hemicelluloses and pulp properties have been changed greatly after xylanase treatment. The results shows that pulp's beating degree, tensile index, burst index and folding degree were decreased with the reduction of hemicelluloses in pulp. Contrarily, opacity and tear index were increased. In addition, the study also revealed that hemicelluloses have an important impact on paper's color reversion value.