APPITA V67No1－January/March 2014 APPITA 2014年第1期中英文摘要

A comparison of fiber and pulp properties of diploid and tetraploid Acacia mangium grown in Vietnam

GRIFFIN A R TWAYI H BRAUNSTEIN R DOWNES G M DO HUU SON HARWOOD C E

SUMMARY:Pulping properties and fibre characteristics of wood from eight-year-old ramets of 6 diploid and 5 tetraploid clones of Acacia mangium grown in Vietnam are reported．Individual clones were represented by two or three ramets．While kraft pulp yield at kappa 20 was very similar for diploid and tetraploids clones，tetraploid clones produced pulp with significantly longer(883 μm)and wider(20．0 μm)fibres，compared to the diploid clones(683 μm and 15．6 μm)．The tetraploid cell wall thickness was greater，resulting in a coarser pulp．Pulmac fibre strengths of the tetraploid were greater than those of the diploid，although their fibre bonding area was lower．The kraft pulp of the best of the tetraploid clones had higher bulk，porosity and tear strength at constant tensile than pulp from a mix of diploid clones and was similar in these traits to softwood pulp．

越南二倍体与四倍体马占相思树 (Mangium)的纤维和纸浆性能比较

GRIFFIN A R TWAYI H BRAUNSTEIN R DOWNES G M DO HUU SON HARWOOD C E

摘 要:本文研究了6个二倍体和5个四倍体的8年生马占相思树 (Mangium)的制浆性能和纤维特性。每个树种取样2个或3个。虽然二倍体与四倍体树种在采用硫酸盐法蒸煮到卡伯值20时的制浆得率非常接近，但与二倍体树种的纸浆纤维尺寸 (长683 μm，宽15.6 μm)相比，四倍体树种的纸浆纤维明显更长 (883 μm)和更宽 (20.0 μm)。四倍体树种的细胞壁更厚，因而纤维粗度更大。虽然四倍体树种的纤维黏合面积较少，但其Pulmac纤维强度要大于二倍体树种。在同等拉伸强度下，最好的四倍体树种所得到的硫酸盐浆比混合的二倍体树种纸浆具有更好的松

厚度、孔隙率和撕裂强度，就这一特性而言，该纸浆与针叶木浆相似。

Characterization of Oxygen Dispersion in Medium-Consistency Pulp Mixing

HEIKKI MUTIKAINEN KARI PELTONEN TAPIO TIRRIJARI KAYHKo

SUMMARY:A new imaging based method for the measurement of oxygen bubble size was tested in both a laboratory mixer and in a pilot-size medium-consistency mixer．The test method was found to be able to measure oxygen bubble size near the outer surface of the pulp bodies．The smallest observed bubbles were slightly less than 10 μm in diameter．Volumetric cumulative bubble-size distribution was found to be the best way to present the data and illustrate mixing efficiency．In addition the effect of different factors such as rotor speed and pulp consistency on the oxygen bubble size was also studied briefly．In laboratory trials softwood and hardwood pulps behaved very differently．Under conditions where bubbles in softwood pulp were very fine，large size bubbles were found in hardwood pulp．The imaging method was also tested in a pilot-loop and it was found that flow velocity and rotor speed of the Proto-mixer by Andritz had a clear measurable effect on the dispersion．Based on the dispersion characterisation，the optimal rotor speed for the Proto-mixer was 1500 rpm and the optimal flow rate 20 L/s．Results also revealed that some coalescence of bubbles occurred immediately after the mixer，as bubble size increased in the piping before entering the reactor．

中浓纸浆混合时的氧分散的特点

HEIKKI MUTIKAINEN KARI PELTONEN TAPIO TIRRIJARI KAYHKo

摘 要:本研究对一种新的基于图像分析测量氧气气泡尺寸的方法在实验室搅拌器和中试规模的中浓混浆机中进行了测试。研究发现，该方法能够测量与纤维外径尺寸相当的氧气泡尺寸。观察到的最小气泡直径略小于10 μm。容积累积气泡尺寸分布法被证明是显示数据并评定混合效率的最佳方式。实验还对混浆机转子速度和浆浓对氧气气泡尺寸的影响进行了简单研究。在实验室条件下，针叶木浆和阔叶木浆的表现非常不同。同样条件下氧气泡在针叶木浆中非常微小，但在阔叶木浆中则很大。在将该方法应用于中试混浆回路时发现:纸浆流速和混浆机 (Andritz公司生产的原型)的转子转速对氧分散有明显的影响。根据对氧分散的定性分析发现:对该混浆机原型机而言，最佳的转子速度为1500 r/min，最佳纸浆流量为20 L/s。结果还显示，离开混浆机之后氧气泡马上发生聚合，导致气泡尺寸在进入反应器之前的管道中变大。

Strategies to reduce heat-induced darkening for enhanced bleachability of mechanical pulps

ANETTE KARLSSON MAGNUS PAULSSON PER ENGSTRAND ERIK HEDENSTRoM

SUMMARY:Under mechanical pulping conditions，elevated temperature initiates reactions in the wood constituents resulting in the formation of coloured structures．In an attempt to reduce the formation of colour，a number of additives have been examined to assess their ability to inhibit heat-induced darkening of a Norway spruce(Picea abies)stone groundwood(SGW)pulp．SGW pulp was used as a model pulp with the purpose of imitating a thermomechanical pulp(TMP)．The heat-treated SGW pulp，both with and without additives present，was subsequently bleached with 4．5%hydrogen peroxide at high pulp consistency and with varying alkali charges in order to examine the hydrogen peroxide bleachability of such pulps．

Heat treatment at 170℃ resulted in a loss of brightness of about 4%ISO after heating for 60 seconds．The reduction in brightness could only partly be regained through high consistency hydrogen peroxide bleaching;the SGW pulp displayed a brightness of 83．7%ISO whereas the heat-treated SGW pulp reached a brightness of 80．4%ISO．

Heat treatment with a low addition rate(1%)of alkaline hydrogen peroxide，sodium bisulphite or sodium sulphite，with a subsequent hydrogen peroxide bleaching stage，resulted in an improved bleached brightness of about 81．6%ISO，i．e．the loss of brightness due to heat was still approximately 2%ISO．Sodium borohydride(1%)did not suppress the thermal darkening but improved the bleached brightness by approximately 2%ISO compared to the heat-treated SGW pulp and resulted in a brightness of 82．6%ISO．Addition of a chelating agent(DTPA，0．11 and 0．45%)and the radical scavengers phthalic hydrazide(1%)and 1-hexanol(1%)suppressed the heat induced darkening somewhat but did not improve the hydrogen peroxide bleachability to any noticeable extent．Addition of citric acid(0．6%)did not suppress the thermal darkening and resulted in impaired bleachability．

抑制热诱导变黑以增强机械浆漂白性能的策略

ANETTE KARLSSON MAGNUS PAULSSON PER ENGSTRAND ERIK HEDENSTRoM

摘 要:在机械制浆条件下，上升的温度会启动木材组分间的反应，导致有色官能团的形成。本实验检验了多种添加剂抑制挪威云杉磨木浆热诱导变黑的能力，以探索减少颜色形成的机理。磨木浆被用作实验纸浆来模拟热磨机械浆 (TMP)。没有添加助剂的参照浆样和添加助剂的浆样经过热处理，随后用4.5%过氧化氢在高浆浓和不同碱用量条件下进行了漂白，以检查这些纸浆的过氧化氢漂白性能。

实验发现，磨木浆在170℃的温度下热处理60 s会导致ISO亮度下降约4%。损失的亮度仅有一部分能通过高浓度的过氧化氢漂白得到恢复;未经热处理的磨木浆ISO亮度为83.7%，而经热处理的磨木浆ISO亮度为80.4%。

在热处理时添加少量 (1%)碱性过氧化氢、亚硫酸氢钠或亚硫酸钠，随后进行过氧化氢漂白，能使磨木浆ISO亮度提高到约81.6%;即由热处理引起的ISO亮度损失仍约2%。与没有任何添加剂的热处理过的磨木浆相比，添加硼氢化钠 (1%)没有抑制热诱导变黑，但提高了漂白浆的ISO亮度约2个百分点 (最终ISO亮度为82.6%)。添加螯合剂 (DTPA，0.11%和0.45%)和自由基清除剂邻苯二甲酸二酰肼 (1%)和1-己醇 (1%)在某种程度上能抑制引起的热诱导发黑，但却没有明显提高过氧化氢漂白性能。添加柠檬酸 (0.6%)没有抑制热诱导变黑，因此导致漂白性能下降。

Analysis of TRS emissions from recovery boilers

ENZO M E P REYESLEONARDO C de OLIVEIRA DANIEL M SATURNINO ESA VAKKILAINEN MARCELO CARDOSO

SUMMARY:This paper analyses the influence of operating variables on flue gas emissions containing total reduced sulfur(TRS)from a dissolving tank and a recovery boiler．Two pulp mills in Chile provided data to allow this study to be conducted．First，at Lincacel plant，emissions from the dissolving tank vent gas scrubber were studied．Then at the Valdivia plant，the influence of different operating variables on TRS emissions from the recovery boiler were analysed using a multivariate statistical analysis for TRS emissions．In this analysis it was observed that variables affecting the boiler furnace temperature were strongly correlated with changes in the TRS emissions．

回收锅炉的总还原硫 (TRS)排放量分析

ENZO M E P REYESLEONARDO C de OLIVEIRA DANIEL M SATURNINO ESA VAKKILAINEN MARCELO CARDOSO

摘 要:文章分析了操作参数对于从溶解槽和回收锅炉排放的含有TRS废气的影响。智利的两个制浆厂对此研究提供了数据。首先，在Lincacel工厂，对溶解槽尾气收集器的废气进行了分析。然后，在Valdivia工厂，使用多元变数统计分析方法，对回收锅炉的TRS排放因操作参数的影响进行了分析。从这些分析中观察到，那些影响锅炉温度的操作参数与总还原硫 (TRS)的排放有强烈的相关性。

Steam，fibre and resin dynamics within a medium density fibreboard(MDF)blowline

KARL MURTON WARREN GRIGSBY ARMIN THUMM

SUMMARY:The effects of blowline steam velocity，resin injection nozzle type and position were determined by injecting fluorescently labelled urea formaldehyde resin into a blowline and examining the resin distribution on the fibre using confocal microscopy．The key results are:

Pressure drop within the blowline is 2．5 times greater with fibre present(normal operation)than for steam only．

Resin coverage increases with greater steam flow through the blowline．

Resin coverage decreased when the resin injection nozzle was shifted from the conventional position after the blowvalve to the end of the blowline．

Resin coverage increases if emulsified wax is mixed with the resin prior to injection．

The blowline steam flow and resin injection position have a greater effect on the resin coverage than the nozzle type for the blowline used．

蒸汽、纤维和树脂在中密度纤维板 (MDF)喷浆管道中的动力学

KARL MURTON WARREN GRIGSBY ARMIN THUMM

摘 要:通过注射带萤光标记的尿素树脂进入喷浆管道，从而判断出蒸汽速度，树脂喷嘴类型及其位置的影响。同时使用了共焦显微镜检测了树脂在纤维上的分布。主要结果为:在喷浆管道内，有纤维时 (正常操作)的压力差是只有蒸汽时的2.5倍;树脂覆盖率随着蒸汽在管道里的流量增加而提升;当树脂喷嘴从原来位于喷浆阀门后的位置移到喷浆管道末端时，树脂覆盖率减低;若在树脂注射前将树脂与乳化蜡混合，树脂覆盖率提高;对此研究中使用的喷浆管道而言，蒸汽流量和树脂注射位置对树脂覆盖率的影响远比树脂喷嘴类型更为重要。