Wood Pulp from New Zealand Timbers.

Progress, Volume XVI, Issue 11, 1 July 1921, Page 256

Wood Pulp from New Zealand Timbers.

RESULTS OF INVESTIGATIONS. Tests to decide the suitability of New Zealand timbers as paper making materials have been carried out recently by the imperial Institute, London, and the report has now been received by the State Forest Service. Samples of paper made from the pulp of New Zealand timbers accompanied the report. These are mainly of the type used in paper-bag making, for, as far as can be gathered from the report, no tests were made to see whether the pulp produced was suitable for newsprint. Discussing the report in a communication to the Commissioner of State Forests, the Director (Captain L. Macintosh Ellis) says that the principal requirements which paper manufacturers hold as desirable in woods for making paper pulp may be summarised as follow : (1) The wood should contain a long, strong, and yet soft and tender fibre. (2) The wood should be relatively free from inter-cellular constituents such as resins, gums, tannins, etc. (3) White fibred woods are preferred, as they bleach more readily. (4) The wood itself should contain large quantities of available cellulose. The eight timbers submitted to the Imperial Institute for examination were as follow : —Black birch (Fagus Solandri), mountain birch (Fagus Cliffotioides), silver or Southland birch (Fagus Menzieii), kamahi (Weinmahnia Racemosa), red birch (Fagus Fusca), tawa (Beilischmedia Tawa), Pinus Laricio, and Pinus Radiata. The chemical

examination and paper-making trials were carried out with wood freed from bark, and the results

throughout refer to the air-dried wood. In the pulping trials the wood was treated with caustic soda under conditions similar to those employed for the preparation of paper pulp on a commercial scale. Results were as follow :

“ The results of the examination,” comments the Director, “ show that the four species of birch yielded pulps of similar character, which bleached readily and furnished fairly strong papers of good quality. The yields of pulp were fairly good (41.5 to 44 per cent.;, that from red birch being the best. The tawa wood also gave a fairly good yield of pulp (42.5 per cent.), and yielded paper of similar quality to that obtained from the species of Fagus. The kamahi wood gave a rather low yield of pulp (36.5 per cent.), which, however, bleached satisfactorily and had good felting properties. The strongest papers were obtained from the woods of Pinus Laricio and Pinus Radiata, but the pulps from these woods did not bleach quite so readily as those from the other six samples. The yields of pulp were, moreover, only moderately good (39 per cent.), and, owing to the presence of numerous knots in the wood, a larger amount of caustic soda was required than was the case with the other timbers. “ All these timbers may, therefore, be regarded as suitable for the manufacture of paper pulp in New Zealand, if available in sufficient quantities, but before the manufacture of pulp is undertaken on a commercial scale a number of factors will need careful consideration. These include (1) The quantity of wood which will be regularly available. In this connection it seems probable from the results of the trials described in this report that the woods of the four species of Fagus and those of tawa and kamahi might be used in admixture. The woods of Pinus Laricio and Pinus Radiata, however, require more drastic treatment, and should therefore not be mixed with the others. (2) The price per ton at which the wood could be delivered at the pulping mill. (3) The selection of a suitable site for the mill. This should be situated in a locality provided with good facilities for transport (by rail or water), and with an ample water supply. (4) The cost of erecting and equipping the mill. (5) The cost of fuel and chemicals. (6) The cost of superintendence and labour. (7) The value of the pulp in New Zealand and Australia as

a substitute for the wood pulp at present imported. These questions will be investigated in detail by the State Forest Service, and a report on the commercial aspects of paper-making furnished cn completion.”—Evening Post.

Fibre. Yield Cellulose. Length. Pulp. Per cent. mm. Per cent Black • birch ••• 57-3 .6 41.5 Mountain birch ... 57.8 •7 41.5 Silver birch ... 55 •7 41.5 Kamahi ... 49 1.0 36-5 Red birch ... ... 55 1.2 44 T awa ... 57.2 1.0 42.5 Finns Laricio ... 63.8 3-4 39 Finns Radiata ... 61.8 2-3 39