Induced Shrinkage and Structural Reorganisation in Ammonia-Treated Wood of Corsican Pine


  • R. W. Coles
  • J. C. F. Walker


Pinus nigra var. calabrica, ammonia treatments, cell-wall crimping, internal swelling, collapse, plasticization, ray parenchyma, shrinkage, anatomy


The ammonia-induced shrinkage of Corsican pine wood (Pinus nigra var. calabrica) was determined over a wide range of temperature, from the melting point (-78 C) to above the critical temperature (132 C) of liquid anhydrous ammonia. The swelling of wood was also measured but over a slightly more limited temperature range. The observed swelling and induced shrinkage of wood are explained in terms of two principal mechanisms: crimping and internal swelling of latewood and collapse of earlywood fibres. Confirmation of these mechanisms was provided by electron microscopy studies. Wood is most effectively plasticized between -5 and -33 C and this would seem to be the optimum temperature range for treating wood.


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