激光打印废纸脂肪酶脱墨的工艺条件

研究脂肪酶对激光打印废纸的脱墨作用,优化脂肪酶脱墨的工艺条件,并与中性脱墨与碱法脱墨进行比较.结果表明,激光打印废纸的脂肪酶脱墨优于中性脱墨与碱法脱墨.脂肪酶脱墨的最佳工艺条件是:碎浆浓度10%～12%,碎浆温度55,℃,碎浆时间40,min,酶用量0.03%,浮选时间8,min.在适宜的脱墨条件下可使脱墨浆ISO白度达到93.42%,残余油墨面积为0.01%.     

不同脱墨方式对二次纤维孔隙结构和结晶性能的影响

采用X射线衍射和等温氮吸附法研究了废旧新闻纸(ONP)在不同脱墨方式下孔隙结构和结晶性能的变化,并运用分形理论对纤维的孔隙结构进行了分析.等温氮吸附实验发现,ONP浆经过中性、碱法和酶法脱墨后,其BET比表面积、BJH孔容及BJH平均孔径变化不大.分形分析发现,脱墨前后纤维的分形维数相近,说明三种脱墨方式对纤维的孔隙结构影响较小. X射线衍射实验发现ONP浆经过中性、碱法和酶法脱墨后,结晶度下降,碱法脱墨浆纤维结晶度下降最大,达12.24%,中性脱墨浆下降6.12%,酶法脱墨浆下降最少仅0.77%.研究中还发现,经过脱墨后,纤维的保水值有所增大,其中碱法脱墨浆纤维增加最大,中性脱墨浆次之,酶法脱墨浆最小.     

脱墨方式对二次纤维孔隙结构和结晶性能的影响

通过X射线衍射分析和低温氮吸附法等方法研究了废旧新闻纸(ONP)浆及经不同脱墨方式脱墨后的脱墨浆的纤维孔隙结构和结晶性能的变化,并运用分形理论对纤维的孔隙结构进行了分析.结果表明:ONP浆经过中性、碱法和酶法脱墨后,其BET比表面积、BJH孔容及BJH平均孔径变化不大;脱墨前后纤维的分形维数相近,脱墨方式对纤维的孔隙结构影响较小;ONP浆经过中性、碱法和酶法脱墨后,结晶度下降,碱法脱墨浆纤维结晶度下降12.24%,中性脱墨浆下降6.12%,酶法脱墨浆下降最少,仅0.77%;经过脱墨后,纤维的保水值有所增大,其中碱法脱墨浆纤维增加最大,中性脱墨浆次之,酶法脱墨浆最小;脱墨后纤维打浆度和平均长度下降较小,细小纤维含量增加.     

ONP脱墨浆二氧化硫脲漂白研究

实验主要探讨了ONP脱墨浆FAS单段漂白的工艺条件,找出了FAS漂白的最佳工艺条件为:FAS用量0.6%,NaOH用量0.3%,漂白温度65℃,漂白时间30min,浆浓10%,在此条件下漂后浆白度达66.6%ISO。     

纤维素酶对混合办公废纸酶法脱墨浆纤维长度和聚合度的影响

研究了不同条件下混合办公废纸纤维素酶脱墨浆的纤维长度、细小纤维含量、纤维长度的分布情况以及纤维平均聚合度变化．结果表明：用单纯的纤维素内切酶脱墨几乎不会导致纤维平均长度下降，而内切酶与外切酶的协同作用会使纤维长度有较大降低；纤维素酶对纤维素聚合度变化的影响很小．     

当代废纸脱墨技术

简要介绍了当今废纸脱墨的工艺和技术，回顾了废纸脱墨的最新进展，对我国的废纸脱墨有一定借鉴之处。     

不同类型及配方脱漆剂脱漆效果的比较

以涂漆木板为实验对象，配制碱性脱漆剂、酸性脱漆剂、有机溶剂型脱漆剂及水性脱漆剂，对木块表面的油漆进行脱除.结果表明，有机溶剂型脱漆剂脱漆效果明显，但其毒性较强；酸性脱漆剂和碱性脱漆剂效果明显，但其强腐蚀性，对于在家庭中进行木器脱漆，有很高的操作要求；水性脱漆剂脱漆时间短，无毒，适用于家庭木器脱漆.     

漆酶/木聚糖酶体系去除废新闻纸脱墨浆中胶黏物的研究

废纸浆因含有大量的细小组分和阴离子杂质,极大地影响了纸机网部的滤水性能和成纸质量。笔者应用漆酶处理废新闻纸脱墨浆,研究其去除胶黏物的效果。结果表明：漆酶/木聚糖酶体系（LXS）处理废纸脱墨浆,能有效去除浆料中胶黏物,尤其是漆酶/木聚糖酶体系处理后碱抽提（LXS+E）去除效果更佳。在酶用量为15 μmol/(min·g)时,LXS和LXS+E处理后与原浆相比,浆中胶黏物分别降低了51.91 %和68.43 %,减轻了后续工序除胶黏物的负荷,改善了浆料滤水性。当漆酶用量为15 μmol/(min·g)时,LXS和LXS+E处理浆与原浆相比,打浆度分别降低了15.22 %和28.26 %。此外通过这两种方法处理还能提高浆料的强度,而浆料得率却稍有下降。     

废纸脱墨纸浆中荧光增白剂的去除及其机理研究

探讨了在纸浆的漂白过程中去除废纸脱墨纸浆中荧光增白剂的可行性,并对其去除机理进行研究,研究结果表明,在脱墨纸浆的漂白过程中,Ｈ２Ｏ２漂剂可以提高脱墨纸浆的白度,但不能有效去除浆中的荧光增白剂．氯漂剂可以有效去除浆中的增白剂,但在本试验的碱性条件下,经其漂白处理后纸浆的白度下降,在ＣｌＯ２漂白脱墨纸浆时,ＣｌＯ２可以氧化纸浆中的荧光增白剂,使其降解为酸类物质,从而使浆中的荧光增白剂得到去除。     

利用废纸生产卫生纸及其质量的探讨

利用废纸生产卫生纸时应针对不同种类的废纸，采用没的工艺和设备，进行脱墨、活活和抄造，生产出Ｂ级卫生纸。     

ENZYMATIC DEINKING OF OLD NEWSPRINT WITH CELLULASES AND XYLANASE

The enzymatic deinking and fiber modification of old newsprint (ONP) with several cellulases and xylanase were investigated and the suitable enzyme candidates were selected for ONP deinking in this paper. The results demonstrated that the cellulases and hemicellulases could significantly improve the deinking efficiency and fiber modification.Moreover, the synergistic effects of Novozym342 and xylanase (HC) can further enhance the deinking performance, reduce the dirt count and improve the brightness of resulting pulp. Additionally, compared to deinked pulps, obtained from conventional chemical materials, enzymatically deinked pulps had better bleachability, and the brightness of the bleached pulp reached 59.1% ISO, 9% ISO higher than the unbleached pulp.     

STUDY ON NEUTRAL DEINKING OF ONP WITH NON-IONIC SURFACTANTS

INTRODUCTIONNeutral deinking is a new deinking technology proposed in recent years. It mainly adopts floatation/washing process in waste recycling. Neutral deinking basically conquers the shortcomings existed in conventional alkaline chemical deinking. Due to its deinking without alkali and other additional agents, it can save deinking costs, reduce environmental pollution and enhance deinking efficiency [1-8].Surfactants are indispensable component in deinking agents. Cationic surfactan…     

HIGH CONSISTENCY PULPING OF OLD NEWSPRINT AND ITS FLOTATION PROPERTIES

INTRODUTIONWaste paper is an important recyclable resource. The problems that are concerned with resource, energy and environment can be solved effectively by recycling of the waste paper. In the past decade, countries all over the world have paid great attention to the recycling of waste paper, so its recycling ratio has been increasing year and year. The technologies for waste paper recycling have also been developed and modified. The production and varieties of paper and paperboard mad…     

FLOTATION DEINKING AGENTS FOR ONP RECLAIMING

Wastepaper reclaiming has received more and more concerns in recent years, and the related science and technology are becoming one of the most research hotspots in China. As an old kind of reclaimed wastepaper, ONP (old newsprint) has many advantages, for example, inks are easy to be separated and removed. Washing deinking, which demands much water consumed, is the main method for ONP reclaiming. But in China many paper mills are affected by lack of water, so they have to select flotation d…     

BIO-DEINKING OF ONP AND ITS EFFLUENT TREATMENT BY WHITE ROT FUNGUS

INTRODUCTIONIt is well known that deinking of secondary fiber can be carried out by chemical or cellulose-degrading enzymes[ 1,2]. However, due to serious pollution produced from chemical deinking and loss of yield affected by cellulosases, new approach for deinking of secondary fiber is expected. White rot fungus is a variety of microorganism that can degrade woody fiber and lignin in natural environment[3,4,5,6], lignin is one of the integrate component in secondary fiber, especially in …     

THE DEINKING OF NON-IMPACT PRINTED PAPER BY COMBINING ENZYME WITH MECHANICAL ACTION

We studied an enzymatic deinking process of non-impact printed paper which was carried out in batch equipment, similar to Valley beater. The equipment can provide suitable forces to cause toner separation from fiber rather than fiber damage. The factors that influenced the deinking efficiency included beating time, pressure between rotating bars and bottom bars, enzyme properties such as dosage,cellulase activity, temperature, pH, etc. Beating time and enzyme type and enzyme dosage was investigated in detail. The deinked pulp was brighter and cleaner. The drainage property also can be controlled by adjusting enzyme dosage and mechanical action strength. Combining enzyme with mechanical action provides the best deinking effects,not enzyme alone. In the meantime, mechanism of enzymatic deinking was discussed depending on the deinked pulp properties.     

废报纸脱墨浆H_2O_2漂前预处理

研究了Na2SO3与DTPA联合用于废报纸脱墨浆H2O2漂前预处理的效果,并与尿素、DTPA、硫酸、EDTA预处理剂的预处理效果进行了比较。结果表明,Na2SO3与DTPA联合是种优良的预处理剂,与其他预处理剂相比,可使漂后浆白度提高1.4%～4.2%ISO。     

ENZYMATIC DEINKING OF NONIMPACT PRINTED WASTES

INTRODUCTIONNonimpact printed wastes include laser printed and xerographic papers. These wastes are increasing with the increasing utilization of computer printout and photocopiers. It is difficult for us to deink these wastes. The pigments in these inks are carbon black mixed with thermo-plastic resin binders,for example, styrene-acrylate copolymers that will crosslink at 100℃during fusing stage of the copying process①. These hard cross linked, stringly bound systems will only be fragm…