A sample rotator accessory repeatably measures the yellowness index of plastic resin pellets. The measurement of plastic pellets is a challenge because they come in a variety of shapes and sizes. For this reason, it is essential to take multiple readings of one sample in order to average the measured values.
The sample rotator is mounted on top of the BYK-Gardner color-view, a 45/0 benchtop spectrophotometer. It uses a rotating system that is powered by the instrument. The pellets are poured into a large sample container simulating an infinite film thickness, and the container is covered by a lid to avoid any influence of ambient light. The Windows-based color control software auto-QC that is supplied with each color-view instrument allows measurement interval time to be set individually dependent on shape and size of pellets.
BYK-Gardner USA, Columbia, MD