THE PULPING AND PAPERMAKING CHARACTERISTICS OF YOUNG L.GMELINI AND B.PLATYPHYLLA

5,10,15,and 20 year old Larix gmelini and Betula platyphylla were used aspulping raw material in the research.The examination of young L.gmelini and B.Platyphyllafibrous structures showed that the fiber length and ratio of length to width of 5 years old L.gmelini noticeably differed from that of mature L.gmelini.but that of 5 year old B.platyphyllawere nearby equal to that of mature B.platyphylla.The research results indicated that 15 yearsold B.platyphylla and 20 year old L.gmelini were best suited to pulping among the eight exper-imental raw materials;10 years old B.platyphylla and 15 year old L.gmelini were optimal tothe ratio of beating degree increment and corresponding beating time.The pulp characteristics of15 year old B.platyphylla and 20 year old L.gmelini were similar to those of mature wood,andit was feasible to consider 15 years to B.platyphylla and 20 years to L.gmelini as their rotationperiod;10 years and 15 years as their thinning cycles for the papermaking forest base.

THE PULPING AND PAPERMAKING CHARACTERISTICS OF YOUNG L. GMELINI AND B. PLATYPHYLLA

5, 10, 15, and 20 year old Larix gmelini and Betula platyphylla were used as pulping raw material in the research. The examination of young L. gmelini and B. Platyphylla fibrous structures showed that the fiber length and ratio of length to width of 5 years old L. gmelini noticeably differed from that of mature L. gmelini. but that of 5 year old B. platyphylla were nearby equal to that of mature B. platyphylla. The research results indicated that 15 years old B. platyphylla and 20 year old L. gmelini were best suited to pulping among the eight experimental raw materials; 10 years old B. platyphylla and 15 year old L. gmelini were optimal to the ratio of beating degree increment and corresponding beating time. The pulp characteristics of 15 year old B. platyphylla and 20 year old L. gmelini were similar to those of mature wood, and it was feasible to consider 15 years to B. platyphylla and 20 years to L. gmelini as their rotation period; 10 years and 15 years as their thinning cycles for the papermaking forest base.