Rapid and nondestructive analysis of quality of prepreg cloth by near-infrared spectroscopy

Quality control of CFRP by means of digital image processing and statistical point pattern analysis

“…The relative difference with respect to a CSR pattern can be computed for g(r) as was done for K(r) in Eq. (14). The resulting plots for E[g (j) (r)], shown in Fig.…”

“…Some researchers have proposed sophisticated and highly technological procedures such as thermal imaging techniques [11,12], optical coherence tomography [13], near-infrared spectroscopy [14,15] or X-ray tomography [16] for the inspection of fiber-reinforced composites. Although these techniques are extremely precise, they usually require high technology machinery, sophisticated interpretation techniques and highly specified and qualified personnel.…”

Use of Near-Infrared Spectroscopy for On-Line Monitoring the Quality of Prepreg Cloth

“…Wei Li, Yu Dong Huang, Ping Chen In our previous work, NIR spectroscopy in conjunction with principal components regression (PCR), and the partial least square (PLS) method was applied respectively to the determination of the quality of alkali-free glass, resurrection glass and carbon/ phenolic resin prepreg cloth [24][25][26][27]. From our experimental results, the accuracy with which prepreg quality could be determined using PLS [26] was generally superior to that obtained when using the PCR method [24]. Compared to the alkali-free and resurrection glass prepreg [25,26], the carbon prepreg [27] gave the relatively inferior determination results due to its weak NIR absorption bands which caused by strong absorption of the carbon.…”

Process Monitoring of Polymer Systems by using Near-Infrared Spectroscopy

“…The application of NIR spectroscopy for monitoring the production of glass/phenolic prepreg (Li et al, 2005;Li et al, 2006a;Li et al, 2008), carbon/phenolic prepreg (Li et al, 2006b) and carbon/epoxy prepreg (Jiang et al, 2007a;Jiang et al, 2007b) has been realized. In the production process of prepreg cloth with solution impregnation method, a FT-NIR spectrometer was assembled between the take-up mechanism and the drying tower, as shown in Fig.…”

“…From the above depiction, it is apparently known that the volatile content could not be determined although the resin content and the pre-curing degree have been monitored successfully by the above mentioned methods. In the opened literatures (Li et al, 2005;Li et al, 2006a;Li et al, 2008), NIR spectroscopy in conjunction with chemometrics method has been applied to the monitoring of the three quality factors of the prepreg cloth.…”