Compression wood structure

Compressed wood-phenolic-formaldehyde composite. Dried treated wood compressed during curing to collapse cell structure Density 1.3 to 1.4. ASE about 95%... 

Nimz H, Robert D, Faix O, Nemr M (1981) C-13 NMR spectra of lignins 8 Structural differences between lignins of hardwoods, softwoods and compression wood Holzforschung 35 16-26... 

Thioacidolysis of extractive-free softwood meal or softwood MWL essentially leads to the guaiacyl structures listed in Table 6 4 2 and referred to previously in the section on thioacidolysis of hardwood lignins When subjected to thioacidolysis, compression wood additionally gives rise to significant amounts of p-hydroxyphenyl QC-, monomeric compounds (Lapierre et al 1987)... 

Hemicelluloses in reaction woods are quite different from those in the normal woods, namely, galactan and P-(l-3)-gIucan in compression wood and galac-tan in tension wood. It is also well known that a remarkable amount of a water-soluble polysaccharide, arabinogalactan, is contained in the heartwood of larch. Since this polysaccharide occurs mainly in the lumen of tracheids and is not a cell wall component, it may not be included in hemicelluloses. Although structures and distributions of hemicelluloses have been comprehensively studied in the last 20 years, their physiologic meanings in a cell wall are not known yet. This must be the most important point for the future study of hemicelluloses. 

Compression Wood. The formation, structure, and chemistry of compression wood have been given considerable attention (see Reference 30 and references cited therein). Compression wood tissue exhibits both major and subtle differences from normal softwood xylem. These differences (Table II) are either directly or indirectly responsible for any distinguishable changes in the behavior and treat-ability of compression wood versus the behavior generally noted for normal wood. 

Nimz, H. H., Robert, D., Faix, O., and Nemr, M. (1981) Carbon-13 NMR spectra of lignins, 8. Structural differences between lignins of hardwoods, softwoods, grasses and compression wood. Holrforschung 35(1), 16-26. 

Properties of the consolidant should be similar to those of the wood structure. The optimal consolidant has hygroscopic and mechanical properties that coincide with the material it is replacing. A consolidant should have approximately the same tensile and compressive strength as wood. A consolidated field enhanced to the point of being too strong is likely to destroy surrounding nonconsolidated materials. 

Burgert, L, K. Fruehmann, J. Keckes, P. Fratzl, and S. E. Stanzl-Tschegg. 2004. Structure-functionrelationships of four compression wood types-Micromechanical properties at the tissue and fiber level. Tree Structure and Function 18 480-485. 

Compreg Compressed wood- phenolic-formaldehyde composite Wood soaked in water or alcohol solution of P-F, dried, heated, and compressed during polymerization cell structure collapsed, density 1.3-1.4, ASE about 95 % resistant to decay strength, hardness, and abrasion increased Cutlery handles, electrical insulators, thin veneers... 

Wood structure within a given tree species is not uniform but varies depending on the conditions under which the tree is growing. For example, trees compensate for exposure to wind or other types of bending pressure by the production of reaction wood. In softwood, the formation of reaction wood is induced on the compressed side of a bending trunk (compression wood), whereas in hardwood, reaction wood is formed on the elongated side of the trunk (tension wood). Reaction wood cells are morphologically similar to normal wood cells but differ in their cell wall structure and chemical composition. 

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