Effect of storage and bleaching of cotton fiber pulp on the stability of Bond paper optical properties

The aim of this study was to investigate the effect of storage and bleaching of cotton fiber on stability of optical properties of Bond paper. For this aim, industrial unbleached cotton fiber pulp with freeness 13°SR, in two types of fix and agitating was stored for 3-15 days in room temperature and after that bleached with hydrogen peroxide. Then, standard handsheets was made from bleached pulp and after air-dried, aged in UV and thermal methods and measured their optical properties. Results showed that agitated samples have more brightness and whiteness and less yellowness than fixed ones and by increasing of storage time this numbers be much and less, respectively. In case of UV treated samples, the brightness and opacity of fixed samples decreased and agitated ones increased. The brightness of fixed and agitated samples with thermal treatment showed up and dawn trend, respectively. Also, UV and thermal treatments, especially in fixed samples lead to much yellowness and much whiteness in agitated ones. Therefore, agitated storage method better than the fixed one so that before and after bleaching present suitable optical properties. In addition, paper made from agitated storage samples has more desirable characteristics and influence of temperature more than UV in present and longtime.