The amount of reinforcement substance in regrind or regranulate can be determined through incinerating the material. The incineration takes place, depending on the material, at temperatures of up to 1000 degree centigrade.
At such temperatures the polymeric material turns into gas or incinerates completely leaving the reinforcement substance behind in the form of ash. The weight of the ash in comparison to the weight of the original material shows the percentage of reinforcement substances in the material, reinforcements such as talcum, fibre glass and marbles etc.
More videos:
Laboratory extruder - MFI Tester - Density Tester - Incinerator - Results

