Quality Wood Studies 



The Ontario Research Foundation obtains an annual grant from the Ontario 

 Government to carry out a quality wood programme. This programme is divided 

 into two spheres of activity: anatomical studies (Dr. L. J. Laddel), and studies of 

 wood chemistry (Dr. G. H. S. Thomas). The function of the Quality Wood Unit is 

 to ensure that the programme carried out by the Ontario Research Foundation is 

 directed to the aims of the steering committee and to relate the findings to field 

 application, thus providing an improved wood supply for industry. In addition, 

 trials are run to assess the natural variation found in specific wood properties such 

 as wood density and spiral grain. 



WOOD CHEMISTRY 



Most recent work undertaken in the pulping area has been a study of the 

 effect of compression wood 1 in black spruce on yield and paper properties. The 

 present investigation has dealt with normal wood, 100% compression wood, and 

 various percentages of compression wood (5% -50%) mixed with normal wood of 

 black spruce. 



There is little doubt from the results, that compression wood is not a desirable 

 raw material from the viewpoint of the pulp and paper industry. Results of the 

 chemical analyses show clearly that the main chemical distinctions between com- 

 pression wood and normal wood are that the compression wood has a substantially 

 higher lignin content and lower cellulose content than comparable normal wood. 

 Under identical pulping conditions (in this instance sodium bisulphite solution), 

 the 100% compression wood pulps were of much lower yield with a higher lignin 

 content than those pulps produced from normal wood. Also, these pulps produced 

 from 100% compression wood were lower in burst, tear, and tensile strength 

 properties. 



However, these results refer to solid compression wood and such material is 

 never likely to form the bulk of the chips used for a commercial cook. The amounts 

 of compression wood normally encountered in black spruce, that is from 5% to 

 10%, can be pulped quite adequately by the same cooking conditions used for 

 normal wood, and although the yield of pulp would be reduced, pulp strength prop- 

 erties are likely to be unaffected. 



WOOD FIBRES 



During the latter part of 1964, work centred on examination of the internal 

 morphology of black spruce and the development and testing of methods. Work 

 was done complementing Dr. G. H. S. Thomas' studies of the behaviour of com- 

 pression wood during pulping and the making of paper, and many measurements 

 were made in an effort to elucidate some of the patterns of variation in normal 

 trees. These latter studies, included an examination of the variation with height 

 within the trees of certain features in the one year ring, and variation outward 

 from the pith. In these studies, which are continuing, a number of features of 

 possible significance to pulp and paper quality were examined. 



A report has been made on the methods basic to the investigation of internal 

 morphology and describes the work carried out so far on compression wood. A 

 second report, covering some of the patterns of variation in normal wood, is forth- 

 coming. 



^Compression wood is a fibre condition of conifers caused by stress. It develops on the 

 underside of leaning tree stems and on the leeward side of stems exposed to wind 

 pressure. 



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