Ability of Near Infrared Spectroscopy to Monitor Air-Dry Density Distribution and Variation of Wood

Authors

  • Brian K. Via
  • Chi-Leung So
  • Todd F. Shupe
  • Michael Stine
  • Leslie H. Groom

Keywords:

Chip, density, near infrared spectroscopy (NIR), wood, pine, statistical process control, pulp yield

Abstract

Process control of wood density with near infrared spectroscopy (NIR) would be useful for pulp mills that need to maximize pulp yield without compromising paper strength properties. If models developed from the absorbance at wavelengths in the NIR region could provide density histograms, fiber supply personnel could monitor chip density variation as the chips enter the mill. The objectives of this research were to a) develop density histograms from actual density versus density histograms developed through NIR modeling, and b) determine the precision of density models developed from absorbance in the NIR region with a recommendation for the sample size needed to estimate the standard deviation of density at a given precision.

Models for density were developed from calibration samples (n = 170) and then validated with 93 randomly held aside samples. The samples were systematically removed from 10 longleaf pine trees of equal age, but different growth rates. The histogram patterns for actual density almost paralleled the histogram patterns developed from predictive models. Subsequently, the validation data set was randomly categorized into groups of three, and the standard deviations of density were measured. For three measurements per data point, the predicted standard deviation covaried with the actual standard deviation of density with an R2 = 0.61 and 0.55 for the calibration and validation data set, respectively. A sample size of 30 was recommended to estimate the standard deviation of density with a precision of 0.01 g/cm3.

References

Antti, H., M. Sjöström, and L. Wallbäcks. 1996. Multivariate calibration models using NIR spectroscopy on pulp and paper industrial applications. J. Chemometr. 10(5-6):591-603.nAxrup, L., K. Markides, and T. Nilsson. 2000. Using miniature diode array NIR spectrometers for analyzing wood chips and bark samples in motion. J. Chemometr. 14(5-6):561-572.nDuffy, G. G., and R. Kibblewhite. 1989. A new method of relating wood density, pulp quality, and paper properties. Appita J. 42(3):209-214.nFarrington, A. 1980. Wood and digester factors affecting kraft pulp quality and uniformity. Appita J. 34(1):40-46nFreund, J. E., and R. E. Walpole. 1980. Mathematical statistics: 3rd ed. Prentice-Hall, Inc., Englewood Cliffs, NJ. 548 pp.nGindl, W., A. Teischinger, M. Schwanninger, and B. Hinterstoisser. 2001. The relationship between near infrared spectra of radial wood surfaces and wood mechanical properties. J. Near Infrared Spec. 9(4):255-261.nGladstone, W. T., A. C. Barefoot, and B. J. Zobel. 1970. Kraft pulping of earlywood and latewood from loblolly pine. Forest Prod. J. 20(2):17-24.nHoffmeyer, P., and J. G. Pedersen. 1995. Evaluation of density and strength of Norway spruce by near infrared reflectance spectroscopy. Holz Roh-werkst 53(3):165-170.nJääskeläinen, A. S., M. Nuopponen, P. Axelsson, M. Tenhunen, M. Löija, and T. Vuorinen. 2003. Determination of lignin distribution in pulps by FTIR ATR spectroscopy. J. Pulp Pap. Sci. 29(10):328-331.nJonsson, P., M. Sjöström, L. Wallbäcks, and H. Antti. 2004. Strategies for implementation and validation of online models for multivariate monitoring and control of wood chip properties. J. Chemometr. 18(3-4):203-207.nKärenlampi, P., and H. SuurHamari. 1997. Classified wood raw materials for diversified softwood kraft pulps. Pap. Puu-Pap. Tim. 79(6):404-410.nKibblewhite, R. P. 1984. Radiata pine wood and kraft pulp quality relationships. Appita J. 37(9):741-747.nKibblewhite, R. P., R. Evans, and M. J. C. Riddell. 1997. Handsheet property prediction from kraft-fibre and wood-tracheid properties in eleven radiate pine clones. Appita J. 50(2): 131-138.nKleppe, P. J. 1970. The process of, and products from, kraft pulping of southern pine. Forest Prod. J. 20(5):50-59.nLabosky, P., and G. Ifju. 1972. A study of loblolly pine growth increments. Part II. Pulp yield and related properties. Tappi J. 55(4):530-534.nMeder, R., A. Thumm, and D. Marston. 2003. Sawmill trial of at-line prediction of recovered lumber stiffness by NIR spectroscopy of Pinus radiata cants. J. Near Infrared Spec. 11(2):137-143.nMichell, A. J., and L. R. Schimleck. 1998. Developing a method for the rapid assessment of pulp yield of plantation eucalypt trees beyond the year 2000. Appita J. 51(6): 428-432.nSchimleck, L. R., and R. Evans. 2003. Estimation of air-dry density of increment cores by near infrared spectroscopy. Appita J. 56(4):312-317.nSchimleck, L. R., A. J. Michell, and P. Vinden. 1996. NIR spectroscopy and principal components analysis. Appita J. 49(5):319-324.nSchimleck, L. R., A. Evans, and J. Ilic. 2001a. Application of near infrared spectroscopy to a diverse range of species demonstrating wide density and stiffness variation. IAWA J. 22(4):415-429.nSchimleck, L. R., A. Evans, and J. Ilic. 2001b. Estimation of Eucalyptus delegatensis wood properties by near infrared spectroscopy. Can. J. For. Res. 31(10):1671-1675.nSchimleck, L. R., A. Evans, and A. C. Matheson. 2002. Estimation of Pinus radiata D. Don clear wood properties by nearinfrared spectroscopy. J. Wood Sci. 48(2):132-137.nSchimleck, L. R., A. Evans, and J. Ilic. 2003b. Application of near infrared spectroscopy to the extracted wood of a diverse range of species. IAWA J. 24(4):429-438.nSchimleck, L. R., R. Stürzenbecher, P. D. Jones, and R. Evans. 2004. Development of wood property calibrations using near infrared spectra having different spectral resolutions. J. Near Infrared Spec. 12(1):55-61.nSwierenga, H., F. Wülfert, O. E. de Noord, A. P. de Weijer, A. K. Smilde, and L. M. C. Buydens. 2000. Development of robust calibration models in near infra-red spectrometric applications. Anal. Chem. Acta 411(1-2):121-135.nTabachnick, B. G., and L. S. Fidell. 1996. Using multivariate statistics: third edition. Harper Collins, New York, NY. 880 pp.nThumm, A., and R. Meder. 2001. Stiffness prediction of radiata pine clearwood test pieces using near infrared spectroscopy. J. Near Infrared Spec. 9(2):117-122.nThygesen, L. G., and S. O. Lundqvist. 2000. NIR measurement of moisture content in wood under unstable temperature conditions. Part 1. Thermal effects in near infrared spectra of wood. J. Near Infrared Spec. 8(3):183-189.nTsuchikawa, S., K. Inoue, J. Noma, and K. Hayashi. 2003. Application of near-infrared spectroscopy to wood discrimination. J. Wood Sci. 49(1):29-35.nVeal, M. A., G. R. Marrs, and M. Jackson. 1987. Control over the quality of loblolly pine chips. Tappi J. 70(1):51-54.nVia, B. K., T. F. Shupe, L. H. Groom, M. Stine, and C. L. So. 2003. Multivariate modeling of density, strength and stiffness from near infrared spectra for mature, juvenile and pith wood of longleaf pine (Pinus palustris). J. Near Infrared Spec. 11(5):365-378.nWülfert, F. W. T. Kok, O. E. de Noord, and A. K. Smilde. 2000. Linear techniques to correct for temperature-induced spectral variation in multivariate calibration. Chemometr. Intell. Lab. 51(2):189-200.n

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Published

2007-06-05

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Research Contributions