INFRARED-SPECTROSCOPY AND MULTIVARIATE CALIBRATION USED IN QUANTITATIVE-ANALYSIS OF ADDITIVES IN HIGH-DENSITY POLYETHYLENE

Different techniques for normalization and calibration of additives in one high-density polyethylene product are compared. The infrared spectra are calibrated against the concentration of three additives. The prediction results from optimized scaling of the raw data are similar to the results using partial least squares regression on data normalized using an internal standard. The performance of three background correction techniques on three other qualities of high-density polyethylene is also compared. By applying background correction techniques a calibration model designed for one product of high-density polyethylene can be used on other products with only a small loss in predictive power.