Continuous powder flow monitoring via near-infrared hyperspectral imaging

The assessment of powder streams, regarding their homogeneity and the occurrence of impurities and agglomerations, is a basis for successful process and environmental monitoring. Diffuse reflectance near-infrared imaging is a high-speed, noninvasive in-line monitoring technique. It allows for acquiring time- and spatially-resolved spectra at short time intervals and at high spectral resolution, which is preconditioned for real-time process monitoring. In this study, a push-broom near-infrared spectral imaging system was used to spatially monitor the (in-)homogeneity and API (active pharmaceutical ingredient) distribution in flowing powders coming from a feeder. Partial least squares regression was used to develop a model for the quantification of the individual mixture ingredients. Moreover, significant influences of the feeder and the particle properties on the ingredients distributions were found. The ultimately developed chemical images provide chemical information about the single mixture components and their spatial distributions.