Measuring nylon carpet yarn heat history by remote NIR spectroscopy part II: Applying remote fiber optic NIR techniques to the manufacturing environment

Part I of this series demonstrated the Near-IR (NIR) method of determining the heat-set temperature (HST) Of carpet yam on bobbins in the laboratory, using a remote fiber optic probe. Part II describes an at-line NIR techniqu e to determine the HST of carpet yam bobbins at three manufacturing sires. At-line NIR measurement of HST is expanded to evaluate the influence of mac hinery and yarn processing factors, environmental factors, and quality diff erences. Optimized Suessen and Superba HST at-line NIR calibrations are dev eloped in the laboratory and successfully transferred and verified on the m anufacturing 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 Ma-determined HST results is thr 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 metho d accuracy. An analytical methodology is presented for developing and trans fering (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, temperatu re and environmental impacts, instrument parameters, and details of the exp erimental process.