Spruce fibers

Fig. 7-3. UV absorbance (222 nm, 0.5 p,m section thickness) by various morphological regions of spruce fibers delignified to various lignin contents by the kraft and acid sulfite method (Wood and Goring, 1973). S, secondary wall P, primary wall CCP, primary wall at the cell corner.

Table I. Composition of Cotton and Typical Angiospermous (Birch) and Gymnospermous (Spruce) Fibers...

In combination with polarization modulation, synchrotron IR microspectroscopy of single spruce fibers Picea abies L.) provided information on hydrogen bonding, orientation, and accessibility of structural units to heavy water and dimethylacetamide applied in a custom-built microfluidic cuvette [106]. A tabulated overview about the assignments of hydrogen bonds and their orientation is also provided by the authors. 

U., Rogge, X, and Grunze, M. (2006) Polarized infrared microspectroscopy of single spruce fibers hydrogen bonding in wood polymers. Biopolymers, 83 (5), 546-555. 

FIG. E-42 Long, strong fibers are a prerequisite for resource-efficient manufacture of strong packaging. The photo shows spruce fibers at a magnification of 100 times. (Source AssiDoman.)... 

The pulp and paper industries use three types of raw materials, namely, hard wood, soft wood, and nonwood fiber sources (straw, bagasse, bamboo, kenaf, and so on). Hard woods (oaks, maples, and birches) are derived from deciduous trees. Soft woods (spruces, firs, hemlocks, pines, cedar) are obtained from evergreen coniferous trees. 

The high percent of unaccounted spray is likely due to filtration of the spray by foliage, and not to drift or evaporation. The effect was pronounced in the Ocala sand pine, a more densely foliated species than the slash pine. Dense foliage acts as fibers in a filter. As the number of fibers increase there are fewer open spaces for drops to penetrate without colliding with a fiber, in this case a needle. As the foliage collects drops at the upper crown there are fewer available to the lower crown levels. These results suggest that pines, even with their sparse foliage compared to spruce and fir, are efficient collectors of spray drops. 

Another report came from Canada in 1959 when Bender published research results of utilizing eastern Canadian barks as furnish for wet-process insulation board and hardboard (33). Bark species included in the study were black spruce and balsam fir each contained 25-35% wood. A Sprout-Waldron disk refiner was used to prepare the bark fiber, and boards were made with lh% wax emulsion but contained no added binder. Physical tests indicated the boards met some commercial specifications the author believed that addition of more woody fiber would improve the properties. In addition, a few experimental dry-process particleboards were made with addition of some unnamed binder that was a byproduct material. 

Further work in Canada to produce rigid wet-process insulation boards from a bark-wood mixture was reported by Branion in 1961 (36). He made boards containing 85% poplar wood and 15% white spruce bark a few boards were made with added poplar or jack pine bark. White spruce bark worked best it appeared to cause a significant increase in tensile strength compared to boards made from 100% poplar wood fiber. This effect also was demonstrated in a hardboard. Other boards were made with up to 80% bark. Water absorption decreased as bark content increased. An effort was made to discover the bark ingredient responsible for the strength increase. After a series of extractions, the active component was concluded to be present in the holocellulose. 

Hietaniemi et al. [76] used a prerelease version of FDS4 to model lire spread on several materials in several different configurations and compared the calculated results with experimental data. This is one of the most comprehensive (in terms of the number of materials and the number of different configurations simulated) large-scale flame spread modeling studies conducted to date. The materials simulated include spruce timber (SBI, room/corner, and 6 m cavity), medium density fiber board (SBI and room/corner), PVC wall carpet on gypsum board (SBI, room/corner), upholstered furniture (furniture calorimeter and ISO room), and polyethylene-sheathed cables in 6 m cavity. 

The resin in the parenchyma cells is mainly composed of fatty acid esters (fats and waxes) and sterols. When wood is pulped, this resin usually remains encapsulated inside the parenchyma cells, while the oleoresin becomes dispersed in the liquor. This is particularly the case with spruce parenchyma cells, which have minute pores and rigid cell walls. Pine parenchyma cells have larger pores and release their resin more readily (Table 5-1). The resin content of acid sulfite spruce pulps can be effectively lowered by fiber fractionation. The situation is different for pine pulps in which the proportion of parenchyma cells is lower. 

TABLE 7 2. Distribution of Lignin in Kraft and Acid Sulfite Fibers of Spruce Earlywooda... 

M. M. Nassar, A. Bilgesu, and G. D. M. MacKay, Effect of inorganic salt on product composition during pyrolysis of black spruce. Wood and Fiber Science, 18(2), 3-10 (1986). 

I. Isolated lignin preparations. Tappi 45 826-829 Boutelje JB, Eriksson 1 (1982) A UV-microscopy study of lignin in middle lamella fragments from fibers of mechanical pulp of spruce. Sven Papperstidn 85 R39-R42 Boutelje JB, Jonsson U (1980) Ultraviolet microscope photometry of pulp fibers. UV-absorbance and its relationship to chlorine number, kapp number and lignin content. Cellul Chem Technol 14 53-67... 

Chemical pulp starts with logs that have had their bark peeled off and that have been reduced to chips. The wood chips are boiled in strong caustic solutions that dissolve away parts of the wood that are not cellulose, such as lignin and resin, and leave the cellulose fibers more or less free. There are two chief processes for producing chemical pulp the kraft process, and the sulfite process. The kraft process uses the wood of either deciduous (e.g., poplar) or coniferous trees (e.g., spruce, fir, and hemlock) and produces a very strong paper. The sul-... 

Figure 5. Cross-sectional view of fully differentiated wood fibers. (A) SE M of a Douglas-fir. Note the thick secondary walls (S) and the fiher lumen (L). (Reproduced from Ref 39. Copyright 1982, American Chemical Society.) (B) TEM of two adjacent fibers in white spruce. Key P, primary wau, S, secondary wall L, lumen and ML, middle lamella. (Reproduced with permission from Ref. 38. Copyright 1974, Forest Products...

S Barsberg and KA Nielsen. Oxidative Quenching of Spruce Thermomechanical Pulp Fiber Autofluorescence Monitored in Real Time by Confocal Laser Scanning Microscopy Implications for Lignin Autofluorescence. Biomacromolecules 4 64-69, 2003. 

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