作为纸浆材的日本落叶松材性及树龄探讨

Study on the Timber Properties and Rotation Age of Larix Kaempferi as Pulpwood

关键词:  日本落叶松  树龄  化学组成  纤维形态  制浆性能

Key Words:Larix kaempferi  tree-age  chemical composition  fiber morphology  pulpability

摘要:本研究对不同树龄的日本落叶松进行了化学组成以及纤维形态分析，同时对相同蒸煮条件下不同树龄的落叶松原料的制浆性能和纸浆物理强度进行比较，以评价日本落叶松作为纸浆材的最佳轮伐树龄。结果表明，在相同制浆工艺条件下（用碱量20%（以Na₂O计）；硫化度25%；液比1∶4；最高温度170℃；升温时间90 min；保温时间150 min，打浆度45°SR），树龄为9~29年的日本落叶松中，17年树龄日本落叶松比较适合作为纸浆材的来源，其中17年树龄的日本落叶松纤维长宽比为77.66、壁腔比为1.11、粗度为0.188 mg/m；17年树龄的制浆细浆得率为42.9%，卡伯值为25.9，残碱为8.14 g/L；制得手抄片的抗张指数81.4 N•m/g，耐破指数6.71 kPa•m²/g，撕裂指数13.7 mN•m²/g，耐折度294次。

Abstract:In order to evaluate the optimal rotation age of Larix kaempferi pulpwood, the chemical composition, fiber morphology, and pulpability of Larix kaempferi pulpwood with different rotation age were analyzed. Specifically, the pulpability was investigated by testing the physical strength of handsheets made from different rotation ages´ Larix kaempferi pulpwoods in the same cooking conditions. The study showed that the 17-year-old Larix kaempferi was much more applicable for pulping under the same pulping conditions(20% alkali charge (Na₂O);sulfidity was 25%; liquid-to-wood ratio was 1∶4; the maximum temperature was 170℃; the heating up time was 90 min; the time at maximum temperature was 150 min; the beating degree was 45°SR）.Particularly, the fiber properties of 17-year-old Larix kaempferi were listed as below: length-to-width ratio 77.66, ratio of cell wall to cavity 1.11, coarseness 0.188 mg/m.The properties of the pulp were as below:yield of screened pulp 42.9%, Kappa number 25.9, and cooking residual alkali 8.14 g/L; the physical strength of handsheets were also listed as below: tensile index 81.4 N·m/g, burst index 6.71 kPa·m²/g, tearing index 13.7 mN·m²/g, and folding endurance 294 times.