Investigation of the impregnation degree of the prepreg by near infrared spectroscopy

In the manufacture of the prepreg, the impregnation degree was a key factor to ensure the quality of the prepreg. In experiment, the impregnation degree of the prepreg was analyzed by developing the reference method. Near infrared (NIR) spectra were combined with partial least squares (PLS) to develop the calibration models of the impregnation degree of the prepreg. The determination coefficient (R-2) was 0.98 and root mean square error of calibration (RMSEC) was 4.24 for the calibration models. The regression coefficient of the actual values against NIR predicted values for calibration model was 0.989. With this rapid and noncontact analytical method, prepreg quality will be improved. (C) 2011 Elsevier Ltd. All rights reserved.