我国南方马尾松与新闻纸生产(论制浆方案的选择)

随着对新闻纸质量要求的提高及新闻纸机车速的加快,在我国南方以马尾松为原料的新闻纸生产中,现有的浆料结构已不能满足要求。化学热磨机械浆(CTMP)因能改善新闻纸质量,同时又可降低生产成本,应得到充分的重视。     

引种四川桤木CTMP制浆工艺及配抄新闻纸

在对引种四川桤木纤维形态和化学组分分析的基础上,通过对浸渍温度、浸渍时间、磨浆浓度和磨浆间隙等因素进行正交试验,提出了引种四川桤木四川桤木CTMP最佳制浆工艺。将漂白后的浆料取代马尾松GP和TMP并与其它浆种配抄成新闻纸。试验结果表明,四川桤木CTMP法制得的成浆适宜配抄新闻纸,成纸的各种性能指标均达到新闻纸优等品国家标准。     

药液回用对针、阔叶材CTMPH2O2两段漂白白度的影响

1实验1.1原料：试验用马尾松木片取自岳阳造纸厂，细叶桉木片取自广东阳江。1.2浆料的制备：马尾松、细叶桉用AndritzSprout－Bauer磨浆中试系统生产CTMP。1.3预处理条件：马尾松原浆白度33.0％及34.6％（ISO），细叶桉原浆白度44.3％（ISO）。实验中，用DTPA对马尾松、细叶桉CTMP预处理。DTPA用量0.25％～0.30％，温度50～60℃，浆浓2％，处理时间20min。1.4漂白条件：漂白在聚乙烯塑料袋中进行，漂白温度70℃，时间2h，浆浓15％～20％。1.5白度测定：取约1.5g绝干浆，使其分散，用水稀释至1％浆浓，在布氏漏斗上抄成浆片，压平…     

新闻纸和机浆印刷纸中将来的配料趋势

过去加拿大只生产新闻纸、轮转凹版印刷新闻纸、电话薄用纸、普通压光磨木浆纸种。现除这些纸种外,还生产含机浆的印刷纸,包括普通压光加填新闻纸、软压光新闻纸、加填和不加填的超级压光纸和轻定量涂布纸。欧洲开始生产大量的轻度染色纸及表面处理纸。现在,新闻纸除用SGW和化学浆的标准配料.也用100％TMP、100％CTMP,两种或两种以上的SGW、PGW、TMP、CTMP、高游离度磺化化机浆(CMP)和化学浆的混合配料。涂布级纸是由磨木浆和外购40％的KP,至少有四种机械浆(SGW、PGW、TMP和CTNP)在工业应用。近年来,机械浆的“家族”激剧增多,以至于高得率浆就多于20种。在较高边缘速度下精磨生产的纸浆,具有较高的散射系数和较低的纤维长度(在一给定能量下)。缓和的亚硫酸盐处理(如CTMP),使节子含量大大低于TMP。磺化程度高制得的纸浆纤维柔韧性大。在印刷纸及新闻纸中用作增强纤维来代替硫酸盐浆。     

红麻CTMP浆在工业纸机上试制新闻纸

用亚利桑那州尤马区生长的红麻在工业精磨机中,为美国新闻出版者协会试制化学热磨机械浆(CTMP),并将该浆在工业纸机上试抄新闻纸,以便对六种日报进行试印并评价其性能。经测定红麻CTMP浆与少量南方松硫酸盐浆混合使用成功地在纸机上运转,抄出的新闻纸在质量上,以及用各种印刷法对各种日报的运转性能上均令人满意。印刷不透明度低于由南方松磨石磨木浆和硫酸盐浆生产的对比新闻纸,对胶版印刷法而言,红麻新闻纸较之对比新闻纸容易掉毛。我们认为这些缺点与红麻CTMP浆生产中的问题有关,而不是所用的原料问题。     

杨木CTMP的生产实践

介绍了吉林造纸厂TMP装置改造成CTMP装置,并增加了过氧化氢漂白设备的情况。改造后,用阔叶材——杨木生产BCTMP,纸浆白度可达66％ISO以上,满足了生产高质量新闻纸的需要。     

过氧化氢漂白高浓度磨木浆在我厂的应用

过氧化氢漂白高浓度磨木浆在我厂的应用广州造纸厂任汝维我厂新闻纸生产是以马尾松为主要原料。马尾松木材蓝变严重，用其生产出来的磨木浆，浆料色泽灰暗，白度一般都较低，特别是使用曾沉在河底的木材生产出来的磨木浆，白度仅有４１～４５％ＩＳＯ，配抄新闻纸后，成纸...     

国外用改性的磨木浆筛渣生产低定量新闻纸

现代化工艺过程生产的机械浆,允许在新闻纸的浆料配比中,化学浆的含量减少到最少,达到5％～10％或不加化学浆。众所周知,国外的一些企业,由100％的TMP生产定量为48.8g/m~2的新闻纸,在45和40g/m~2新闻纸的浆料配比中,化学浆分别为5％及10％。在前苏联,新闻纸的生产企业,计划在第12个五年计划末期投产TMP及CTMP,因而新闻纸的基本组成在目前仍然是传统的磨石磨木浆。     

国外用改性的磨木浆筛渣生产低定量新闻纸

现代化工艺过程生产的机械浆,允许在新闻纸的浆料配比中,化学浆的含量减少到最少,达到5％～10％或不加化学浆。众所周知,国外的一些企业,由100％的TMP生产定量为48.8g/m~2的新闻纸,在45和40g/m~2新闻纸的浆料配比中,化学浆分别为5％及10％。在前苏联,新闻纸的生产企业,计划在第12个五年计划末期投产TMP及CTMP,因而新闻纸的基本组成在目前仍然是传统的磨石磨木浆。     

红麻制CTMP浆试验

本试验的目的旨在以红麻代替木材为原料制作CTMP代替化浆配抄新闻纸,因此进行了红麻的原料分析、红麻磨浆试验与比较、红麻浆的漂白试验、红麻浆配抄新闻纸的试验与比较。试验结果表明:红麻原料较之冷云杉、杨木等更易于预处理;纤维平均长度虽不及冷云杉,但较杨木长与水竹相近;成浆得率可达84.96％,强度较好,特别是撕裂指数高达8.5mN·m~2/g,白度则略低于木材CTMP与SGW,需通过漂白加以提高。红麻CTMP可以代替或部份代替化学浆配抄新闻纸。也可根据需要,分别以木质部与韧皮部或不同配比生产不同品种的CTMP。     

Über die Eignung von thermo-mechanischem und chemo-thermo-mechanischem Holzstoff (TMP und CTMP) aus Buchen- und Kiefernholz für die Herstellung von mitteldichten Faserplatten (MDF)

Medium density fibreboards (MDF) were made from beech in laboratory and pilot plant scale from thermo-mechanical (TMP) and chemo-thermo-mechanical pulps (CTMP) using both melamine reinforced urea-formaldehyde resin (UF-resin) and diphenylmethane diisocyanate polymers (PMDI). The physicalmechanical and chemical properties of the boards were evaluated. From the results the following conclusions can be drawn:

1. Both TMP and CTMP led, on using UF-resin, to MDF with very high mechanical properties exceeding the required values in European standards.
2. Pulping temperature seems to have an influence on the mechanical properties of the boards, prepared from TMP and CTMP. Increasing the pulping temperature from 150°C to 170°C negatively affects the mechanical board properties, whereas the properties of MDF from CTMP (sulfonic group content between 0.2% and 0.3%) increases by elevating the maximum pulping temperature from 150°C to 170°C.
3. The pulping chemicals in the CTMP-process (Na₂SO₃ and/or NaOH) decrease the formaldehyde release from the boards, as they act as scavengers for formaldehyde.
4. Due to higher deacetylation degree during CTMP process, MDF made from CTMP release more than 4 times acetic acid than MDF from TMP. The release of formic acid is quite different, it is in MDF, made from TMP higher than in MDF from CTMP.
5. MDF with very high mechanical properties can also be made from beech pulps (TMP) using PMDI. PMDI in combination with a formaldehyde scavenger in the middle layer and UF-resin in the surface layer leads to boards with very low formaldehyde release.

     

Über die Eignung von thermo-mechanischem (TMP) und chemo-thermomechanischem (CTMP) Holzstoff aus Buchen- und Kiefernholz für die Herstellung von mitteldichten Faserplatten (MDF)

Medium density fibreboards (MDF) were made from thermomechanical (TMP) and chemo-thermo-mechanical pulps (CTMP) derived from pine wood. As a binder a melamine reinforced urea formaldehyde resin (UF-resin) and diisocyanate polymers (PMDI) were applied. The mechanical-technical properties of the boards as well as some of their chemical properties were evaluated. The results of the investigation led to the following conclusions: MDF from CTMP showed in general higher mechanical properties (bending strength) compared to MDF from TMP. Moreover, the formaldehyde release of the CTMP-boards was lower. This may be due to the formaldehyde scavenging properties of the used pulping chemicals during the process of CTMP. MDF from CTMP showed much higher release of acetic acid compared to MDF from TMP. This is likely to higher deacetylation of the wood substance during CTMP process compared to the TMP technique.     

Chemische Eigenschaften von TMP und CTMP, hergestellt aus Kiefernholz und UF-Harz-gebundenen mitteldichten Faserplatten (MDF)

Thermo-mechanical (TMP) and chemo-thermo-mechanical pulps (CTMP) were prepared from pine wood and from UF-bonded MDF made from pine wood. For preparing TMP pine chips as well as UF-bonded MDF were digested under pressure at 170 °C. Thereafter, the digested chips and MDF were defibrated at 170 °C using a single disc refiner. CTMP was prepared from pine wood with 0.25% NaOH (based on dry wood) under the conditions set forth above. CTMP was also made from MDF under two conditions using 0.15% sodium hydroxide (% based on dry MDF) and a mixture of sodium sulphite (1%) and sodium hydroxide (0.25%). The pulps show distinct differences in their properties: TMP from UF-bonded MDF shows lower extractive content in cold and hot water, lower pH-value and higher buffering capacity towards alkali of the cold water extractives than the CTMP counterpart. Moreover, CTMP prepared by using sodium hydroxide alone as a pulping agent increases the content of formate and acetate ions in the cold water extractives. The use of a mixture of sodium sulfite and sodium hydroxide as a pulping agent decreases, however, significantly the content of formate and acetate ions in the cold water extractives. This may be due to the buffering action of sodium sulfite. In general, CTMP decreases the formaldehyde release of the fibres, as measured by the flask method. In presence of sodium sulfite as a pulping agent for recycled MDF, the formaldehyde release is slashed to almost 30% of its original value. The formaldehyde release of CTMP from UF-bonded boards seems to be in the same range as that of TMP from virgin wood.      

Benetzung von TMP und CTMP aus Holz sowie gebrauchten mitteldichten Faserplatten (MDF)

TMP (thermo-mechanical pulps) and CTMP (chemo-thermo-mechanical pulps) were made from pine wood and recycling MDF, which has been prepared from pine wood too. The fibres were tested for their wettability using the method developed by Roffael et al (2002). The results reveal that TMP are much less wettable in comparison to CTMP from the same wood. Moreover, fibres made from UF-bonded MDF by the TMP- and CTMP-process are of much higher wettability compared to TMP and CTMP prepared directly from wood. No significant difference in the wettability between TMP and CTMP from UF-bonded MDF was detected. This behaviour has been attributed to the fact that the UF-resin in MDF degrades during thermohydrolytic pulping leading to the formation of ammonia and free urea. Therefore, pulping of UF-bonded boards takes place under chemo-thermo-mechanical conditions (CTMP).     

利用机械浆生产木质纳米纤维素

开发了一种可以利用机械浆细小纤维组分生产纳米纤维素的方法,并对木质纳米纤维素粒径分布进行表征。本次研究使用了Cril表征技术,测定TMP纳米纤维素和CTMP纳米纤维素Crill值,作均质化时间的函数。结果显示,TMP-NLC和CTMP-NLC的Crill值都与均质化时间相关。本研究的另一目的是使用木质纳米纤维素作为纸和纸板的增强剂,加入到CTMP和BKP浆料内,结果显示,在手抄片紧度相似的情况下,加入木质纳米纤维素后纸页的Z向强度和其它一些重要的机械性能指标都有所改善。     

液体包装纸板原纸的研究

本文通过实验阐述了使用斯堪的纳维亚云杉ＣＴＭＰ和松木ＢＫＰ配抄液体包装纸板原纸时，浆料的配比和游离度变化对浆料中纤维筛分含量、液体包装纸板原纸（面、芯、底三层）的物理强度指标的影响，并通过电子显微镜和光学显微镜观察，对纤维形态和相互间结合情况进行了研究，从而探索了ＣＴＭＰ适宜的配用量和合理的游离度范围。     

Potential of pulp and paper secondary sludge as co-adhesive and formaldehyde scavenger for particleboard manufacturing

This study investigated the potential of secondary sludge (SS) as urea–formaldehyde (UF) co-adhesive for particleboard manufacturing. Three proportions of SS from three conventional pulping processes were added in the formulation of particleboard manufacturing. A 3³ factorial design was used. All panels were tested for thickness swell (TS), linear expansion (LE), internal bond strength (IB), flexural modulus of elasticity (MOE), flexural modulus of rupture (MOR) and formaldehyde emission. Results indicated that particleboards made with SS from thermomechanical pulp (TMP) and kraft pulp (Kraft) met the ANSI standards for LE, IB, MOE, and MOR (with 7 and 9 % UF). However, the TS of panels made with SS was higher than that of control panels and adding SS to the formulation affected negatively this property. Most of the properties studied in the particleboards made with SS from chemical–thermomechanical pulping (CTMP) process failed to meet the ANSI standards. The main advantage of using SS as co-adhesive is the reduction of formaldehyde emission, in the best case here, about 50 %, with CTMP sludge added, of the particleboards.     

Influence of pulping process on the emission of formaldehyde and volatile organic acids from pulps and medium density fibreboards (MDF)

Cold water extracts from pulps produced by the chemo-thermomechanical technique (CTMP process) contain higher amounts of formate and acetate ions compared to cold water extracts from pulps produced by the thermo-mechanical process (TMP process). The CTMP shows a higher emission of acetic acid than the corresponding TMP. However, the release of formic acid is lower than that from TMP due to the higher pH-value of CTMP. Furthermore, the release of formaldehyde from CTMP is lower than that from TMP due to Cannizzaro reaction catalysed by alkali. Moreover, binderless fibreboards from CTMP are significantly lower in the formaldehyde release compared to binderless boards from TMP. The use of MUF-resin increases the formaldehyde release of the boards from TMP and CTMP. Furthermore, MUF-bonded boards from TMP and CTMP are of higher pH-value and lower emission of formic and acetic acid.     

用于配抄液体包装纸板原纸的SCAN云杉CTMP和桦木BKP浆料性能的研究

本文阐述了使用ＳＣＡＮ云杉ＣＴＭＰ和桦木ＢＫＰ配抄液体包装纸板（ＬＰＢ）时，浆料的配比和游离度对液体包装纸板芯层和液体包装纸板原纸物理强度指标的影响。通过实验及电子显微镜和光学显微镜对ＬＰＢ原纸表面和截面的纤维结合形态的观察，证明了用ＣＴＭＰ代替漂白化学浆与桦木ＢＫＰ配抄ＬＰＢ芯层是可行的，并探索了ＣＴＭＰ适宜的配用量及合理的游离度范围。