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REFERENCE LINKING PLATFORM OF KOREA S&T JOURNALS
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Journal of Korea Technical Association of The Pulp and Paper Industry
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Journal DOI :
Korea Technical Association of the Pulp and Paper Industry
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Volume & Issues
Volume 31, Issue 5 - Dec 1999
Volume 31, Issue 4 - Dec 1999
Volume 31, Issue 3 - Sep 1999
Volume 31, Issue 2 - Jun 1999
Volume 31, Issue 1 - Mar 1999
Selecting the target year
The Role of Fungal Laccase in Biodegradation of Lignin
Andrzej Leonowicz ; Jolanta Luterek ; Maria W.Wasilewska ; Anna Matuszewska ; M.Hofrichter ; D.Ziegenhagen ; Jerzy Rogalski ; Cho, Nam-Seok ;
Journal of Korea Technical Association of The Pulp and Paper Industry, volume 31, issue 5, 1999, Pages 1~11
Wood components, cellulose and lignin, are degraded simultaneously and the general outline for the complementary character of carbohydrates and lignin decomposition as well as the existence of enzymatic systems combining these processes is still valid. The degradatiion of free cellulose or hemicellulose into monosaccharides has long been known to be relatively simple, but the mechanism of lignin degradatiion wasn ot solved very clearly yet. Anyway the biodegradation of woold constituents is understood at present as an enzymatic process. Kigninolytic activity has been correlated with lignin and manganese peroxidases. At present the attention is paid to laccase. Laccase oxidizes lignin molecule to phenoxy radicals and quinones . This oxidation can lead to the cleavageo f C-C or C-O bonds in the lignin phenyl-propane subunits, resulting either in degradation of both side chains and aromatic rings, or in demethylation processes. The role of laccase lies in the "activation" of some low molecular weight mediators and radicals produced by fungal cultures. Such activated factors produced also in cooperation with other enzymes are probably exported to the wood environment where they work in degradation processes as the ' enzyme messengers." It is worth mentioning that only fungi possessing laccase show demethylating activity. Thus demethylation, the process important for ligninolysis, is probably caused exclusively by laccase. Under natural conditions laccase seems to work with other fungal enzymes , mediators and mediating radicals. It has shown the possibility of direct Bjrkman lignin depolymerization by cooperative activity of laccase and glucose oxidase.
Enzymatic Deinking of Old Newsprit with Alkalophilic Enzymes from Coprinus cinereus 2249
Lee, Jung-Myong ; Eom, Tae-Jin ;
Journal of Korea Technical Association of The Pulp and Paper Industry, volume 31, issue 5, 1999, Pages 12~17
This study was to evaluate applications of the alkalophilic enzymes from Coprinus cinereus 2249 with old newsprint(ONP). A enzymatic deinking process based on alkalopholic enzymes was investigated . It was found that alkalophilic enzymes could effectively deink old newsprint. When applied on deinking of the old newsprint, it increases the freeness and brightness due to effect of hydrolysis at 0.1% enzyme concentration . Also, the physical properties of deinked pulp were improved.
The Effects of Multiple Recycling on Deinkability, Optical and Physical Properties of Recycled Paper
Shin, Jun-Seop ; Min, Choon-Ki ;
Journal of Korea Technical Association of The Pulp and Paper Industry, volume 31, issue 5, 1999, Pages 18~23
This study examined the effects of multiple recycling on deinkability and properties of recycled paper from laser computer printout(LCPO). First, alkaline paper with a 20% printed area was disintegrated by TAPPI standard disintegrator. After dewatering , the pulp was followed by flotation, handsheet making, and drying at room temperature, in order. A sequence of printing , disintegrating, flotating , handsheet making and drying was one recycling cycle and this cyclic treatment was repeateed from zero to five times. The residual ink content in recycled handsheets by SEM-EDXA and Py-GC analyseswas increased slightly as recycling number increase. After five cycles of recycling the ISO brightness of recycled handsheets dropped to about 90% of the original brightness. However, it had a gain of 10% in opacity. The most of physical properties of recycled handsheets were decreased as recycling numbers increase except of for tear strength.
Development of Crosslinked Cational Starches and Evaluation of Their Performance in the Microparticle Retention System
Kim, Tae-Young ; Lee, Hak-Lae ;
Journal of Korea Technical Association of The Pulp and Paper Industry, volume 31, issue 5, 1999, Pages 24~30
Crosslinked corn starches were prepared to increase their molecular weights and their performance as a component of Compozil system was evaluated and compared with that of potato starches. It was shown that greater improvements in retention and strength properties could be achieved when crosslinded cationic corn starches rather than conventional cationic potato starches were used especially at high conductivity because of their molecular rigidity.
Influence of Shrinkage and Stretch During Drying on Paper Properties
Torbjorn Wahlstrom ;
Journal of Korea Technical Association of The Pulp and Paper Industry, volume 31, issue 5, 1999, Pages 31~46
A drying paper strives to shrink due to the shrinkage of the individual paper fibres. Laboratory results show that a reduction of the shrinkage or an imposed stretch leads to a large increase in tensile stiffness and a large decrease in strain at break. In c cylinder drying section the water in the web is repeatedly heated on the drying cylinder and evaporated in the free draw. To evaluate the drying process regarding influence on paper properties these sub-processes, or drying phases, have to be studied separately. The effect of the conditions on the drying cylinder and on the VacRoll is investigated in pilot trails. Both the fabric tension on the drying cylinder and on the VacRoll reduces the shrinkage of the paper. The laboratory results are used as input to a numerical simulation of the conditions in the free draw. If the web width is increased or the length of the free draw is reduced the mean shrinkage of the paper web is reduced . However, the difference in shrinkage between the middle and the edge of the web is increased.
Characterization of Tensile Energy Aborption in Paper
Park, Jong-Moon ; James L. Thorpe ;
Journal of Korea Technical Association of The Pulp and Paper Industry, volume 31, issue 5, 1999, Pages 47~56
Tensile energy absorption in paper has long been measured as the area under the load-elongation curve. Little effort has been made to define where and how that energy is used within the paper itself. Characterization of tensile energy absorption in paper is discussed. Multiple small elements within newsprint and kraft sack have been defined and the energy absorbed in those elements are discussed. The tensile profiles of the weak paper, newsprint, and the tough paper, kraft sack, are presented as separate strain profiles, stress profiles, and strain energy density profiles. This allows a complete analysis of the energy absorption of both papers for comparison or contrast.
Yield and Fracture of Paper
Park, Jong-moon ; James L. Thorpe ;
Journal of Korea Technical Association of The Pulp and Paper Industry, volume 31, issue 5, 1999, Pages 57~72
Traditional theories of the tensile failure of paper have assumed that uniform strain progresses throughout the sheet until an imperfection within the structure causes a catastrophic break. The resistance to tensile elongation is assumed to be elastic , at first, throughout the structure, followed by an overall plastic yield. However, linear image strain analysis (LISA) has demonstrated that the yield in tensile loading of paper is quite non-uniform throughout the structure, Traditional theories have failed to define the flaws that trigger catastrophic failure. It was assumed that a shive or perhaps a low basis weight area filled that role. Studies of the fracture mechanics of paper have typically utilized a well-defined flaw around which yield and failure could be examined . The flaw was a simple razor cut normal to the direction of tensile loading. Such testing is labeled mode I analysis. The included fla in the paper was always normal to the tensile loading direction, never at another orientation . However, shives or low basis weight zones are likely to be at random angular orientations in the sheet. The effects of angular flaws within the tensile test were examined. The strain energy density theory and experimental work demonstrate the change in crack propagation from mode I to mode IIas the initial flaw angle of crack propagation as a function of the initial flaw angle is predicted and experimentally demonstrated.
Distortion and Dilatatioin in the Tensie Failure of Paper
Park, Jong-Moon ; James L. Thorpe ;
Journal of Korea Technical Association of The Pulp and Paper Industry, volume 31, issue 5, 1999, Pages 73~85
Yield and fracture are separated in the tensile failure of paper. Failure in the machine direction of photocopy paper is contrasted with failure in the cross-machine direction . The ratios of distortion (shape change) to dilatation (volume change) for individual elements at yield and fracture are described. The ratios of distortion to dilatation are measured and compared to predicted values of the strain energy density theory. To evaluate the effect of the angle from the principal material direction on the strain energy density theory. To evaluate the effect of the angle from the principal material direction on the strain energy density factor, samples are prepared from machine direction to cross-machine direction in 15 degree intervals. the strain energy density of individual elements are obtained by the integration of stress from finite element analysis with elastic plus plastic strain energy density theory. Poison's ratio and the angle from the principal material direction have a great effect ion the ratio fo distortion to dilatation in paper. During the yield condition, distortion prevails over dilatation . At fracture, dilatation is at a maximum.
Modeling and Optimizing Brightness Development in Peroxide Bleaching of Thermomechanical Pulp
Wang, Li-Jun ; Park, Kyoung-Hwa ; Yoon, Byung-Ho ;
Journal of Korea Technical Association of The Pulp and Paper Industry, volume 31, issue 5, 1999, Pages 86~94
Alkaline peroxide bleaching of chemi-mechanical pulp is a very complicated system where various process factors affect the bleacing performance and pulp properties. Traditional onefactor-at a time method is ineffective and costly infinding the optimal bleaching conditions. In this study, statistical experimental design and multiple regression method wre used to investigated the interactions among various bleaching factors and to find out the possbile maximal brightness development during one stage alkaline peroxide bleacing of TMP. The TMP was made from 10% Korean red pine and 90% Korean spruce and had an initial brightness of 54.5% ISO. the TMP was pretreated with EDTA(0.5% on O.D. pulp, 3% pulp consistency, 30
for 60 minutes) and bleached in a 2 L Mark V Quantum Reactor at 750 rmp, 7.5% of bleaching consistency and with 0.05% magnesium sulfate addition. The ranges of chemical factors studied , based on oven-ried pulp, were 1-5% for hydrogen peroxide, 1-4% for sodium hydroxide and 1-4% for sodium silicate. The rages of reaction temperature and time were 50-90
and 40-180minutes respectively. Interactions of hydrogen peroxide with alkali , time with temperature ature, alkali with time and silicate with temperature were found to be significant which means that hydrogen peroxide bleaching will be favored at stable concentration of perhydroxyl ion, relatively short time and low temperature, and high level of silicate. Mathematical model which has good predictability for target brightness in one stage peroxide bleaching can also be established easily. Base ion the model, maximal brightness of 70% ISO was found to at 50
and 50 minutes by chemical additions of 5% for hydrogen peroxide, 3.2-3.4% for sodium hydroxide and 4% for silicate based on O.D. pulp. However, this result might not be suitable for situation where furnishes are different from ours, or different pretreatment is used, or bleaching carried out at different pulp consistency. In these cases it will be good to re-investigate the process by a similar methodology as was used in this study.
Screening of Wood-Rotting Fungi for Efficient Decolorization of Draft Pulp Bleaching Effluents
Lee, Seon-Ho ;
Journal of Korea Technical Association of The Pulp and Paper Industry, volume 31, issue 5, 1999, Pages 95~100
In order to find fungi having high treatment activity of kraft pulp bleaching (E1) effluent without any additional nutrietns, 124 strains of white-rot fungi were isolated from decayed wood samples. The author isolated five fungi(KS-62, MZ-400 , YK-719, YK-472 and Phanerochaete sordida YK-624) having high-decolorization activity of the E1 effluent. Particularly, the fugus KS-62 show the high effect of the decolorization and the degradation of the chlorinated lignin in the E1 , effluent compared with Coriolus versicolor and Phanerochaete chrysosporium.