NEW ZEALAND FLAX

Greymouth Evening Star, 14 November 1930, Page 12

NEW ZEALAND FLAX

MAKING OF PAPER.

The New Zealand flax is suitable for high-grade fine paper and strong wrapping paper is the opinion expressed by the United States Bureau of Standards after samples had been examined. The official report of the Paper Division of the Bureau is as follows:— “Both laboratory and semi-commer-cial paper-making experiments were made through a test procedure essentially the same as that generally observed in paper production. Test cooks of the flax were made, using as reducing agents caustic soda, caustic soda and sodium sulphide combined, and sodium sulphite and caustic soda separately. “Good bag or wrapping paper pulp was produced by cooking the flax with the caustic soda process, using comparatively small amounts of caustics (10 per cent.). With larger amounts of caustic (25 per cent.), the pulp could be bleached with about 14 to 16 per cent, of bleach, and was then suitable to use in admixture with other pulps in making fine papers. “In the semi-commercial tests, the yield of air-dried unbleached pulp from the twenty-five per cent, unbleached pulp from the 25 per cent, caustic cook of unscutched New Zealand flax was 57.2 per cent., based on the bone-dry weight of the flax, while the laboratory test yielded 57.7 per cent. This shows a very close checking of results as to yield between the laboratory and semi-commercial tests when similar cooking conditions and amounts of chemicals were employed. “When 10 per cent, of caustic was used the yield of unbleached pulp was 77.4' per cent. However, this pulp was suited only for wrapping paper, as contrasted with the pulp obtained from the 25 per cent, caustic soda cook which could be bleached and the resultant pulp made satisfactory for use in fine paper. Unscutched flax cooked with 15 per cent, of caustic soda and 10 per cent, of sodium sulphide combined gave a yield of 62.2 per cent. The pulp obtained was satisfactory for use in wrapping paper”