Patent ID: 8302777
Filing Date: 2012-11-06
Classification: B29B,B29K,Y02W

Abstract:
1. A method for reducing the content of a heavy metal in a mixture of solid plastic materials, wherein the mixture includes plastic flakes and there are at least two different colors of plastic flakes in the mixture, the method comprising: determining a percentage of each of two or more colors of flakes in the mixture; predicting a heavy metal content in the mixture by multiplying the determined percentage for each color with an estimated heavy metal concentration for that color to obtain a heavy metal contribution for each color and adding the heavy metal contributions of each color; determining whether the predicted content of the heavy metal in the mixture exceeds a pre-determined threshold; and if the predicted content exceeds the pre-determined threshold, performing a color sorting step to obtain a subset of the mixture of plastic flakes, wherein the subset of the mixture of plastic flakes has a lower heavy metal content than the mixture prior to the color sorting step.