近红外光谱无损测定纸张施胶度的研究

Study on Nondestructive Determination of Sizing Degree of Paper by Near Infrared Spectroscopy

采集不同施胶度(Cobb值)纸张的近红外光谱,通过不同方式对所采集的近红外光谱进行预处理。选择最佳预处理方式,利用偏最小二乘法(PLS)建立测定纸张施胶度的校正模型。结果表明,最佳预处理方式为减去一条直线(SLS),最佳波数区间为5446.3～12493.4 cm^(-1)和4246.8～4424.2 cm^(-1),得到校正模型的内部验证数据集以及外部验证数据集的相关系数R^2分别为0.9186和0.9085,内部交叉验证均方差R_(MSECV)和外部验证均方差R_(MSEP)分别为0.640和0.439,外部验证的预测结果与标准值之间的最大相对偏差为4.81%。校正模型有较高的测定精度和较好的推广性,为纸张施胶度无损伤、无预处理的快速、简便、准确检测提供新的途径,并且可望实现纸机的在线检测。

The near infrared spectrum of paper with different sizing degrees（Cobb value） was collected and pretreated through different ways,then the best pretreatment way was selected and partial least squares（PLS） was used to establish calibration model of paper sizing degree （Cobb value）.The result showed that straight line subtraction（SLS） was the best pretreatment way,and the best wave band were 5446.3～12493.4 cm^（-1） and 4246.8～4424.2 cm^（-1）;The correlation coefficients（R^2） of the calibration model and external authenticate model were 0.9186 and 0.9085;R_（MSECV） and R_（MSEP） of the calibration model in cross-validation were 0.640 and 0.439,respectively;The maximum relative deviation between the external authenticate predictive value and the standard value was 4.81%.The model established with near infrared spectroscopy（NIR） and PLS was an accurate,non-destructive method for paper detecting rapidly and easily,and on-line testing of paper sizing degree in paper machines was expected to be realized.