Aging at Tropical Condition and its Effect on Deinking Potential of ONP, 2002 Fall Technical Conference

The effect of aging was investigated at laboratory scale, but in different conditions: laboratory condition and natural condition. At laboratory condition, accelerated aging technique was followed. For natural condition, the same storage conditions of tropical mills were applied, but in a smaller scale. It was found that the storage temperature has the major effect on pulp brightness, however, the other parameters such as sunlight, UV, moisture, …etc can not also be overemphasized. Outdoor storage but covered is recommended for storing the ONP for no longer than one month; for the storage of longer than one month indoor storage is recommended. Outdoor storage without any coverage (under direct sunshine or rain) was found to be the most harmful storage option for ONP. The comparison of the two aging processes suggested that the accelerated aging does not reproduce tropical condition. The conditions required for processing of aged ONP - pulping time, pulping temperature and surfactant dosage - were thoroughly discussed.