强韧竹木混合未漂长纤浆生产实践

Production Practice of Unbleached High Strength Long Fiber Pulp Mixed with Phyllostachys Pubescens in Masson Pine

关键词:  楠竹  马尾松  混煮  纸张强度

Key Words:phyllostachys pubescens  masson pine  mixed cooking  paper strength properties

摘要:采用硫酸盐超级间歇蒸煮，研究了在马尾松中掺配不同比例楠竹对纸浆性能及纸张质量的影响。结果表明，新鲜楠竹1%NaOH抽出物含量高达25%~30%，蒸煮初期碱耗较高，且楠竹灰分、氯离子、二氧化硅含量分别是马尾松的3.2倍、3.4倍和3.5倍；楠竹与马尾松混合蒸煮后，渣节量明显上升，且渣节中竹浆含量很少，掺配蒸煮时应注意碱分配，避免循环残碱过低造成木片蒸煮不均匀；当楠竹掺配比例为20%~30%时，合适的用碱量为17.8%~18.2%（活性碱，以Na₂O计），白液硫化度26%~30%，温充、热充、蒸煮阶段用碱量分配比为15%∶25%~30%∶60%~55%，蒸煮最高温度158~160℃，H因子1050~1150，浆料卡伯值35~40；在马尾松木片中掺配30%以内的楠竹对纸浆强度没有明显影响，但在相同打浆度下PFI磨转数明显下降；长时间运行时需适当加大碱炉碱灰外排量以减少氯钾离子富集；通过筛分使长短纤维分别利用，是实现竹浆高值化应用的关键。

Abstract:The effects of mixing ratios of bamboo chips （phyllostachys pubescens） in masson pine chips on pulp properties and paper qualities were investigated using a sulfate super batch cooking process. The results showed that the extractives content by 1% NaOH solution of fresh bamboo chips was about 25%~30%， the alkali consumption was higher at the initial stage of cooking， and the contents of ash， chloride ion & SiO₂ were 3.2， 3.4 and 3.5 times higher than those of masson pine chips， respectively. After the mixed cooking of bamboo and masson pine chips with comparison to masson pine chips cooking alone， the amount of knots & rejects increased significantly， and the content of bamboo strips in rejects was very small. Attention should be paid to alkali distribution during different stages of cooking to avoid uneven cooking of wood chips caused by low circulating residual alkali. When bamboo mixed ratio was 20%~30%， the appropriate alkali consumption was 17.8%~18.2% （AA， as Na₂O）， the sulfidity was 26%~30%， the alkali distribution ratios were 15%∶25%~30%∶60%~55% for warm black liquor∶hot black liquor∶cooking， the maximum cooking temperature was 158~160℃， the H factor was 1050~1150， and the Kappa number of the pulp was 35~40. The paper strength properties were insignificantly changed while bamboo chips proportion was within 30%， but the number of PFI rotations decreased obviously at the same beating degree. When running for a long time， it was necessary to increase external displacement of the alkali ash to reduce the enrichment of chloride and potassium ions. The key to high-value-added applications of bamboo pulp was separating pulp into long-fibre and short-fiber fractions by screening.