Near infrared finds contaminants in wool

17 Jun 2002

Australian scientists are working with near infrared (NIR) and advanced data processing to detect polyethylene and polypropylene contaminants in wool.

Small pieces of polymer become entangled with the sheep fleeces on the farm. If the contaminants are not found they will appear as white flecks in the dyed wool.

The Commonwealth Scientific Industrial Research Organisation (CSIRO) wanted to develop a high speed detector system to replace people in the tedious job of finding the scraps and removing them. They demonstrated the principle by combining NIR spectroscopy and an analytical technique called principal component analysis (PCA).

PCA is a statistical data technique that identifies the components that account for variances within a data set, in this case NIR spectrograms of wool, contaminants and mixtures of wool and contaminants. PCA is become more and more widespread in industry and the CSIRO work demonstrates its effectiveness with NIR spectroscopy. JB