On-line monitoring quality index of carbon/phenlic resin prepreg cloth by means of near infrared spectrum

Resin content, volatile content and soluble resin content of carbon/phenolic resin prepreg cloth were on-line monitored by means of near infrared diffused reflectance spectrum. Partial least square method was used to establish calibration models, choose spectral preprocessing methods and number of PLS factors. The t-test results for unknown sample show that there is no significant difference between the near infrared method and the standard method. The near infrared method can predict three indexes simultaneously and analyze single sample within 1 minute. The analysis results can be used to adjust processing parameters of the prepreg during manufacture. The investigation results show that near infrared diffused reflectance spectrum analysis is a kind of accurate and effective method for quality control of carbon/phenolic resin prepreg cloth.