Measuring Nylon Carpet Yarn Heat History by Remote NIR Spectroscopy. Part II: Applying Remote Fiber Optic NIR Techniques to the Manufacturing Environment

Abstract

Part I of this series demonstrated the Near-IR (NIR) method of determining the heat-set temperature (HST) of carpet yarn on bobbins in the laboratory, using a remote fiber optic probe. Part II describes an at-line NIR technique to determine the HST of carpet yarn bobbins at three manufacturing sites. At-line NIR measurement of HST is expanded to evaluate the influence of machinery and yarn processing factors, environmental factors, and quality differences. Optimized Suessen and Superba HST at-line NIR calibrations are developed in the laboratory and successfully transferred and verified on the manufacturing floor. Very good agreement is obtained between the stated HSTS and NIR-determined HSTS for samples with a wide range of HSTS and routine production samples, which exhibit quality differences in manufacturing. The major influence on NIR-determined HST results is the temperature and %RH in the manufacturing area; the NIR calibration can be readily adjusted with a control bobbin to offset these environmental effects without loss of method accuracy. An analytical methodology is presented for developing and transfering (verifying and validating) NIR measurements from a laboratory to an at-line analysis in the manufacturing area. Operational concerns and other procedural details include sample matrix effects, data treatment, temperature and environmental impacts, instrument parameters, and details of the experimental process.