Yellowing of Chemical Pulp by Adding Glucuronoxylan

Generally, aging of paper is evaluated by folding endurance and degree of yellowing. It was known as that lignin, hemicellulose and metallic ion affect yellowing of mechanical or chemical pulps. Among these elements, especially, the study of hemicellulose that affect at yellowing of pulp is insufficient. In this study, we examined into the influence that glucuronoxylan or glucomannan and metallic ion($Cu^{2+},\;Fe^{2+},\;Fe^{3+},Mn^{2+}$) residued in pulp get each or when mixed at yellowing. Filter paper was treated with each metallic ion, glucuronoxylan and the mixture of glucuronoxylan and metal ions, and brightness and CIE $L^*a^*b^*$ was measured after accelerated aging. As the results of measurements, the filter paper processed by 10% glucuronoxylan was dropped 2-3% on the brightness after accelerated aging for 24 hours. Also, the filter paper treated with glucuronoxylan and $Fe^{2+}$ was dropped 7% on the brightness.