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1928. NEW ZEALAND.

PULP AND PAPER MAKING (REPORT ON INVESTIGATIONS INTO SUITABILITY OF SELECTED NEW-ZEALAND-GROWN WOODS FOR).

Laid on the Table of the House of Representatives by Leave.

CONTENTS. page Pulping Tests— continued. page Letter from the Director of Forestry to the Sulphite Pulping Studies — continued. Hon. the Commissioner of State Forests .. 4 Discussion of Results— Results .. . . .. .. .. 4 Rimu .. .. .. :. .. 16 Purpose of Tests .. .. .. .. 4 Insignis Pine .. .. .. 17 Location of Study .. .. .. ..4 Tawa .. .. .. .. ..18 Future Programme .. .. .. .. 5 Tawa - Insignis Pine Mixture .. .. 19 Letter from the Engineer in Forest Products European Larch .. .. .. 19 to the Director of Forestry .. .. 5 Adaptation of Experimental Results to MillGeneral : — scale Operation .. .. .. .. 19 Summary .. .. .. .. .. 6 . Commercial p u i p _ m jll Trials— Significance 0 Goneral 2() History .. .. .. .. o Sulphite Pulp-mill Equipment .. ..20 Standards of Comparison 7 Cooking-conditions 20 Material job Tests :- Discussion of Results 20 Selection of Woods 7 Pulp.yields 20 Collection— Summary of Sulphite Pulping Studies .. 21 First Shipment for Laboratory Semi-oommeroial J " Tests .. .. .. .. .. 7 Alkaline and Semi-oommeroial Pulping Studies— Second Shipment for Mill Trials .. .. 8 Objectives and Scope of the Work .. .. 21 Physical Properties of the Woods .. ..8 ProcessesPhysical Properties of the Wood-fibres .. 9 The Soda Pulping Process .. ..21 Chemical Properties of the Woods .. ..9 The Sulphate, or Kraft, Pulping Process .. 21 Idlping _1 touts:— The Semi-la-a.it Pulping Process .. ..22 Objectives .. .. .. .. ..J The Semi-chemical Pulping Process .. 22 Preparation of Wood— Experimental Equipment and Procedure .. 22 At Laboratory .. .. .. ..a Discussion of Results .. .. ..22 At Imp-mill 10 Soda Pulping Tests 23 Groundwood Pulpmg Studies- Sulphate Pulping Tests 23 The Groundwood Process .. .. Semi-kraft Pulping Tests .. .. 23 Factors affecting Quality of Groundwood .. 10 Semi-chemical Pulping Tests .. .. 23 Laboratory Semi-commercial Tests- Summary of Alkaline anil Somi-chemical Pulping ' Selection of Woods .. .. ..11 Tests °3 Grinder Equipment and Methods of Tests .. II Tests used to determine Quality of Pulp .. II Papermaktnc. Tustm : Grinding of Insignis Pine and Spruce .. 12 General . . .. .. .. .. 24 Grinding of Tawa .. .. ■■ 12 Newsprint Standards.. .. .. ..24 Microscopic Classification of Groundwood Pulps 12 Laboratory Semi-commercial TestsCommercial Grinding Trials at Ladysmith Pulp- Standard Newsprint from Insignis Pine .. 24 mill — Newsprint from Tawa, Insignis Pine, Rimu, and Selection of Woods .. .. .. 13 European-larch Mixtures .. .. 25 Grinder Equipment and Method of Test .. 13 Tawa Sulphite, Tawa Groundwood, and The Grinder-runs— Insignis-pine Sulphite Mixtures .. . . 25 Grinder-run No. 1 .. .. ..13 Substitutions of Rimu and European Larch 26 Grinder-run No. 2 .. .. ..14 for Insignis-pine Sulphite .. ..26 Grinder-run No. 3 .. .. .. 14 Newsprint Runs using semi-chemical Pulps .. 26 Pulp-yields .. .. .. ..14 . Physical Qualities of Tawa Groundwood Pulp 14 Commercial Paper-mill. TrialsSummary of Groundwood Pulping Studies .. 15 General .. •' •' ... • ■ •■ *6 Sulphite Pulping Studies- Paper-maclime Runs at Ladysmith . .26 Objectives and Scope of Work .. ..15 Papermachme Runs at Wisconsin Rapids .. 27 The Sulphite Process 15 Discussion of Results .. ..28 Laboratory Pulping Studies- Summary of Papcrmakmg Studies .. .. 29 Previous Work .. .. .. .. 16 Significance of Studies : — Method of Attack . . .. .. 16 Conclusions .. .. .. .. .. 29 Equipment and Manipulation .. .. 16 Recommendations .. .. .. .. 30 Materials used .. .. .. ..36 Acknowledgments .. .. .. ..30

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