Three-Dimensional Analysis of the Collapse Behavior of Kraft-Cooked Norway Spruce Fibers
Keywords:Picea abies, 3D, reconstruction, kraft, fibers, collapse, cross-sectional compactness
AbstractComputerized reconstruction and measurement of cross-sectional compactness were used to analyze the collapse behavior of fibers in a kraft-cooked fiber bundle containing early- and transition wood fibers. The results show that the collapse behavior of delignified fibers may be determined by fiber structure and dimensions, and how these are affected by the action of external forces. Nevertheless, some deformation may also arise from internal stresses during drying. Cross-sectional compactness was shown to correlate with the collapse resistance of fiber walls. Results show that the collapse behavior of thin-walled fibers with similar cross-sectional compactness values may vary greatly along the fiber axis. Cross-sectional compactness was relatively higher and constant along the fiber axis for fibers with thick cell walls. Fibers with thin cell walls showed lower values of cross-sectional compactness, which seem to decrease towards the middle of the fiber. Cross-sectional compactness seems to increase towards the fiber tips. Fiber ends may become flattened after delignification independently of high values of cross-sectional compactness. Computerized 3D reconstruction techniques may be a valuable tool in understanding the collapse behavior of pulp fibers.
Bardage, S. L. 2001. Three-dimensional modeling and visualization of whole Norway spruce latewood tracheids. Wood Fiber Sci. 33(4):627-638.nBergander, A., and L. Salmén. 2000. Variations in transverse fibre wall properties: Relations between elastic properties and structure. Holzforschung 54(6):655-661.nEvans, R., R. P. Kibblewhite, and S. Stringer. 1997. Kraft pulp fiber property prediction from wood properties in eleven radiata pine clones. Appita J. 50(1):25-33.nGindl, W., and R. Wimmer. 2000. Relationship between lignin content and tracheid morphology in spruce. Pages 163-168 in H. C. Spatz and T. Speck, eds. Plant Bio-mechanics, Freiburg-Badenweiler, Aug. 27-Sept. 2.nHult, E.-L., P. T. Larsson, and T. Iversen. 2001. Cellulose fibril aggregation—An inherent property of kraft pulps. Polymer 42:3309-3314.nJang, H. F., and R. S. Seth. 1998. Using confocal microscopy to characterize the collapse behaviour of fibers. TAPPI 81(5): 167-173.nJang, H. F., R. C. Howard, and R. S. Seth. 1995. Fiber characterization using confocal microscopy—The effect of recycling. TAPPI 78(12): 131-137.nKauman, W. G. 1964. Cell collapse in wood. Part 1: Process variables and collapse recovery. Holz. Roh-Werkst. 22(5):183-196.nKibblewhite, R. P. 1999. Designer fibers for improved papers through exploiting genetic variation in wood mi-crostructure. Appita J. 52(6):429-435.nKibblewhite, R. P., and K. A. Hamilton. 1984. Fiber cross-section dimensions of undried and dried Pinus radiata kraft pulps. N.Z. For. Sci. 14(3):319-333.nMiller, P. 1989. Fiber and sheet properties resulting from refining stock concentration variation. Appita J. 42(2): 125-130.nPage, D. H. 1967. The collapse behaviour of pulp fibers. TAPPI 50(9):449-455.nPaakari, T., and R. Serimaa. 1984. A study of the structure of wood cell by X-ray diffraction. Wood Sci. Technol. 18:79-89.nRobertson, A. A. 1963. The physical properties of wet webs. Sven. Papperstidn. 66:477-497.nSahlberg, U., L. Salmén, and A. Oscarsson. 1997. The fibrillar orientation in the S2-layer of wood fibres as determined by X-ray diffraction analysis. Wood Sci. Technol. 31:77-86.nSirviö, J. 2001. Variation of cross-sectional properties within single Norway spruce tracheids. Wood Fiber Sci. 33(1):16-25.nSirviö, J., and P. Kärenlampi. 1998. Pits as natural irregularities in softwood fibers. Wood Fiber Sci. 30(1):27-39.nSpurr, A. R. 1969. A low viscosity embedding medium for electron microscopy. J. Ultrastruct. Res. 26:31-43.n
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