Patent ID: 9638683
Date: 2017-05-02
CPC Classifications: G01N

Claim:
1. A method for determining a percentage of recycled polyethylene terephthalate present in a test sample using a computer comprising: receiving in the computer, a selection of a contaminant from a plurality of contaminants; identifying by the computer at least one predictor analyses from a plurality of predictor analyses as being a statistically independent predictor analyses of a presence of the selected contaminant using a binary logit model in non-transitory computer readable media, wherein the binary logit model includes test sample analytical data received from at least one of a plurality of analytical systems for analyzing the test sample and producing the test sample analytical data; performing a prediction of a percent recycled polyethylene terephthalate statistical model by the computer, based on the at least one predictor analyses, performing the prediction including determining a probability corresponding to the percent recycled polyethylene terephthalate using a logic link function in non-transitory computer readable media; performing an identification by the computer of at least one set of best subsets of the statistically independent predictor analyses of percent recycled polyethylene terephthalate, using a finite sample corrected Akaike Information Criterion function in non-transitory computer readable media to produce a plurality of subset models; performing a refinement by the computer of the percent recycled polyethylene terephthalate statistical model to a final predicted percent recycled polyethylene terephthalate model, including comparing each of the plurality of subset models to identify one of the plurality of subset models having minimum value relative fit using a refinement function in non-transitory computer readable media and rescaling the selected best subset so that the smallest mixed distribution logit-type model is rescaled to 0; and identifying and outputting the percent recycled polyethylene in a test sample using the final predicted percent recycled polyethylene terephthalate model, wherein the plurality of analytical systems for analyzing the test sample include at least one of a mechanical stress tester, a differential scanning calorimeter, an ultraviolet visible spectroscope and an inductively coupled plasma-atomic emission spectroscope.