Paper Made from Kauri

Sun (Auckland), Volume III, Issue 721, 22 July 1929, Page 8

Paper Made from Kauri

Pulp Tests with Waste Woods

EXPERIMENTS which have been conducted by the Imperial Institute, London, on behalf of the New Zealand State Forest Service, reveal bright possibilities for the profitable use of waste kauri wood for paper-making.

Early tests with the extracted resin, also, are extremely encouraging, and research is being continued to insure full utilisation of these properties.

The possibility of using waste kauri wood as a paper-making material, either in its natural state or after the extraction of the resin, has been considered in New Zealand for some time, the experiments in other woods carried out through the State Forest Service having revealed the likelihood of established industries here in the comparatively near future. Recent commentators discounted the possibilities of New Zealand ever becoming a great paper-producing country on account of its manufacturing conditions, but the tests which the Imperial Institute have conducted, and which are set out in a statement issued by the State Forest Service, indicate at least that waste kauri could, if properly treated, be brought into commercial use, and that its resinous properties also could be turned into valuable products. It was recognised at the outset that the Question whether iL would be profitable to deresinate the wood before pulping would depend on the cost of extracting the resin and the market value of the product. Investigations have also been carried out at the Imperial Institute regarding the nature and uses of the extracted resin. In addition, papermaking trials have been made with a sample of “fossil” kauri wood, from which the resin had been extracted by means of alcohol, in comparison with ordinary kauti wood. Extracting the Resin Experiments were undertaken with five samples of wood, and it was found that, while the pulps were composed of coarser and longer fibres than those of coniferous wood-pulp, the yields of pulp obtained from deresinated woods were very satisfactory. The results, the Forest Service states, show that kauri wood represented by the various samples submitted could be converted into paper pulp of satisfactory quality either in the original condition or after the removal of the resin. Two of the samples were found to contain a large quantity of resin, and it was possible, owing to the comparatively low yield of pulp In these cases, that manufacture might not prove remunerative unless the resin could be extracted and marketed at a satisfactory price. It seems possible that wood containing less than 10 per cent, of resin might be converted into pulp without previous deresination.

The institute has suggested to the New Zealand Government that observations might be made with a view to determining whether any relation exists between the percentage of resin in the wood and the age of the trees, or other factors. It might facilitate the treatment of the wood if it could be roughly separated into two groups, one of which could be pulped in the original condition, whereas the other might need deresination in orctgr to make its treatment remunerative. So far as “fossil” wood was treated, it was shown that paper of good quality and strength generally similar to that obtained from the fresh product, could be secured. The waste wood held from 7 per cent to 20 per cent, of resin. Utilisation of by-products led to the making of varnish of equal weights of the extracted resin and alcohol. When applied to sized wood they dried rapidly, giving tough, hard. rather dark-coloured, lustrous coats, which showed no signs of cracking after several weeks’ exposure. Further Research Urged Samples of resin were submitted to manufacturers and merchants, all of whom urged further experimental research to raise its commercial value. “The results of this investigation indicate that the resin extracted from waste kauri wood would be saleable in this country and that it might realise about £4 or £5 a cwt.”, the report goes on. “It must be borne in mind, however, that these valuations are only tentative, and that a definite opinion cannot be given until technical trials have been made by manufacturers on a large scale. “It was pointed out to the New Zealand authorities that if, in view of the results given in this report and of those of the paper-making trials, it is considered worth while to proceed further with the object of utilising this kauri wood for the manufacture of paper pulp with the extracted resin as a by-product, it will be necessary for at least scwt. of the resin to be extracted either in New Zealand or in this country, in order that complete-technical trials may be carried out to determine definitely its commercial value and possibilities. It may be mentioned that the resin extracted from the “fossil” kauri wood is superior to that described above and which was obtained from the waste wood, resembling more the ordinary kauri gum of commerce.”