纸浆白度的快速测定方法

A Method for Rapid Determination of Pulp Brightness

基于浆料水分、湿压片、定量和玻璃片等因素对纸浆白度测定值的影响,提出了一种纸浆白度的快速测定方法。结果表明,当浆料水分含量超过60%时,水分含量对湿浆片的白度测定值产生较大影响;湿浆压片处理使湿浆白度测定值略有下降,但是可显著提高湿浆白度测定的重现性;定量对纸浆白度的测定值没有影响;玻璃片对湿浆白度测定值产生的影响是恒定的。通过对白度在30%～90%范围内不同种类浆料的湿浆白度与其风干浆片和纸片白度测定值进行测定比较,发现它们之间存在很好的线性相关,可分别由校正模型y=98.1x-101(R2=0.9798)和y=89.1x-82.5(R2=0.9889)来描述和计算。该方法简单、重现性和准确性好,适用于生产过程中对纸浆白度的快速测定。

A rapid method for pulp brightness determination is reported in this paper.The effects of several parameters including the pulp moisture content,pulp sheet basis weight,the pulp treatment ways（pressing and covering a glass on the pulp sample） on the measuring result of the wet pulp were investigated.The results showed that the moisture content of the pulp is a major factor affecting the brightness measurement of the wet pulp,especially at water content greater than 60%.Although pressing can decrease the measured brightness of the wet pulps,the reproducibility in brightness measurement can be improved.Two calibration models for the brightness of air-dried pulp and paper,respectively,are established,i.e.,y=98.1x-101（R2=0.9798） and y=89.1x-82.5（R2=0.9889）,and their brightness can be rapidly determined based on the corresponding pressed wet pulp samples ranging from 30%ISO to 90%ISO.The present method is simple,reproducible and accurate;it is suitable to be applied for rapid determination of pulp brightness on production line.