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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 33, Issue 5 - Dec 2001
Volume 33, Issue 4 - Dec 2001
Volume 33, Issue 3 - Sep 2001
Volume 33, Issue 2 - Mar 2001
Volume 33, Issue 1 - Mar 2001
Selecting the target year
Paper Strength Mechanism Depending on Mixing Ratio of Softwood and Hardwood Fibers
Journal of Korea Technical Association of The Pulp and Paper Industry, volume 33, issue 3, 2001, Pages 1~8
Paper consists of fiber network and paper properties were highly affected by fiber characteristics. Many researchers have tried to relate fiber and paper properties. Softwood and hardwood fiber's are quite different in their properties. Generally, softwood fiber's are longer and more flexible than hardwood fibers. At present, many paper mills make mixed paper with softwood and hardwood fibers except for special grade. During fracture some fiber's are broken and others are pulled out. In this paper, the number of broken and pulled out fiber's during fracture is analyzed depending on the mixing ratio of softwood and hardwood fiber's. Fiber length, curl, kink, coarseness, WRV and formation index were measured. Double-edged strength samples were prepared to observe the number of broken and pulled out fiber's. Mixed paper strength was decreased with increasing hardwood fibers ratio. During fracture, softwood fiber's were more likely broken and hardwood fibers were more likely pulled out. The strength of paper which consists of softwood fibers was determined by fiber's broken strength and that of hardwood fibers by fiber's debonding strength. Paper strength was changed depending on the fiber's bonding capability. If the fiber is longer and more flexible, the fiber network becomes stronger and stiffer.
Effect of Retention System on the Characteristics of Floc and Retention
Journal of Korea Technical Association of The Pulp and Paper Industry, volume 33, issue 3, 2001, Pages 9~17
The floc characteristics of base paper stock for coating by the retention aid system consisting of polyacrylamide (high molecular weight low charge density, HMLC) and PEI without and with anionic inorganic oxide (IO) were investigated under various shear conditions of MDDA (modified dynamic drainage analyzer). The floc size was increased with cationic electrolytes dosage whatever inorganic oxide is applied or not. The effect of inorganic oxide on the floc size showed the different result between PAM and PEI. The smaller floc was obtained by PAM without inorganic oxide, but larger floc was obtained by PAM with inorganic oxide. However, the effect of shear force was not observed. Floc formation index was decreased by the addition of cationic electrolytes with or without inorganic oxide. Floc formation index had better correlation format formation index than floc size. The relationships between wet web permeability and mat air permeability showed the significant linear correlation (
=0.97~0.98) for HML PAM and PEI. Floc formation index gave more useful information than the retention measurement when the performance of retention aids is evaluated at the laboratory before applying at the paper mill.
Effect of Ozonation Consistency on the Ink Removal Efficiency and Pulp Characteristics
Journal of Korea Technical Association of The Pulp and Paper Industry, volume 33, issue 3, 2001, Pages 18~23
The effect of pulp consistency on the deinking properties in the ozone deinking of ONP was investigated in order to develop the environmentally friendly deinking method. The pulp consistency and ozone treatment time were varied for this purpose. Higher pulp consistency during ozone treatment gave better ink removal efficiency than the conventional deinking method. In was also found that the increase of pulp consistency can decrease the ozone treatment time which can meet the deinking quality. WRV of ozone deinked pulp obtained at 10% and 30% of pulp consistencies was lower than those of the conventional deinking method. However, the higher pulp consistency during ozone treatment improved WRV. Highest brightness was obtained at the ozone treatment condition of 30% pulp consistency and 10 minutes. The lower brightness at the other ozone treatment condition should be originated from the excessive decrease of ink particle size and then decrease of true ink removal efficiency. Scott bond was increased with the increase of pulp consistency and treatment time. However, the improvement of breaking length with ozone treatment was no significant.
Ozone Deinking Mechanism of White Ledger
Journal of Korea Technical Association of The Pulp and Paper Industry, volume 33, issue 3, 2001, Pages 24~28
The utilization of wastepaper as a papermaking raw material is everlastingly required for the environmental protection of earth. However the recycling of wastepaper for this purpose cause another problem such as the increasing of the load of wastewater treatment, lower strength properties of paper, and poor printability, etc. The interest in the development of the environmentally friendly deinking technology is increased continuously. Thus, our research team have tried to apply the ozone to the deinking of white ledger and ONP, and obtained the positive results which can be considered as an alternative method for the conventional deinking method. The purpose of this study is to investigate the mechanism of ozone deinking. Styrene acrylate and polystyrene were treated with ozone and measured the change of molecular weight with the GPC. The molecular weight distribution obtained with GPC showed only slight increase by the ozone treatment, and gel formation by the polymerization was observed. Therefore the removal of ink particles with ozone treatment seems to be facilitated by the increase of the brittleness and decrease of adhesive property.
Studies on the Pore of Coating Layer and Printability (IV) -Effects of Blending Ratio of Pigments-
Journal of Korea Technical Association of The Pulp and Paper Industry, volume 33, issue 3, 2001, Pages 29~36
This paper was made to evaluate the effect of the blending ration of GCC and No. 1 clay on the printability by investigating the structure of pore such as the pore rate, the number of pores, pore size and distribution of coated paper. The coated structure is mainly depended on the results of correlation between pigment and binder. It means that the structure of the pore occurred is chiefly affected by the blending ratio of GCC and No. 1 clay. This physical properties of the pore have a close relation with ink set-off associated with the drying rate and the penetration in ink into base paper and with printing gloss. Therefore it was needed to find out how the pore structure and the printability will be changed by modifying the blending ratio of GCC and No. 1 clay to vary the pore structure of coated paper. Below are the results of measurement: As the blending ratio of clay going up, water retention, sedimentation volume. smoothness, and paper gloss were increased, but relatively brightness and opacity were decreased. Pore rate was the highest at the blending ratio of No. 1 clay to GCC, 70:30. In this case, average pore radius was also increased. Ink receptivity and K&N ink receptivity were improved with the increase of the blending ratio of GCC, where was, ink setting was vice versa. No difference was observed in the weight of ink, but ink repellance decrease with the decrease of blending ratio of GCC.
Comparison between PY and YP on Bleach Efficiency of White Ledger according to Deinking Method
Journal of Korea Technical Association of The Pulp and Paper Industry, volume 33, issue 3, 2001, Pages 37~43
The bleach efficiency between PY and YP bleaching of pulps, which were deinked in neutral (cellulase) and alkaline (NaOH, NaOH/
) ranges, and were treated on kneader, was compared in this study. The brightness of pulps (84.8~88.4% ISO) which were deinked in alkaline or neutral ranges increased up to 88.4%~88.8% ISO after PY or YP bleaching. There was no difference in the brightness between PY and YP bleaching. And the dirt count of bleached pulps was similar each other at the range of 17~38 ppm. The tensile index of bleached pulps was slightly higher in PY bleaching than those in YP bleaching. While with the treatment of kneading, the brightness and dirt count decreased remarkably compared to those of no-kneading. However, the sharp difference in the brightnesses or in dirt count of bleached pulps decreased after bleaching. The brightness of bleached pulps at YP stages was only numberically higher than those at PY stages without regard to the treatment of kneading. Therefore, in the case of the neutral deinkiing process, the conversion of PY bleaching stages to YP bleaching stages was profitable to water loop system, and was harmless in the aspect of the bleach efficiency.
Studies on the Determination of Optimal Flocculation Condition in Wastewater of Recycled Paper
Journal of Korea Technical Association of The Pulp and Paper Industry, volume 33, issue 3, 2001, Pages 44~51
Sedimentation characteristics such as SS,
, COD removal efficiency of waste water in the toilet paper mill using milk carton were examined. Optimum dosage of coagulant, rapid mixing time and slow mixing time were determined by turbidity, SS, COD,
and then equation for treatment efficiency was suggested. Mechanical strength of floc was determined by turbidity. For the coagulant, polyacrylamide (PAM) is more efficient for removing pollution than the aluminium sulfate. Effective mixing ratios of PAM and aluminum sulfate to remove pollution are 70:30 and 30:70. The lowest turbidity was showed when rapid mixing at 300 rpm after coagulant injection was applied. That which indicates the highest point of flocs mechanical strength.
Effect of Grape-Bagging Paper Properties on Saccharinity of Grape
Journal of Korea Technical Association of The Pulp and Paper Industry, volume 33, issue 3, 2001, Pages 52~58
The aim of using grape-bagging paper is preventing damages by light and harmful insects during grape growth. The number of using grape-bagging paper has been increasing because advantages of using it have been confirmed. A technology to produce it has not been fully developed yet. In this study properties of the grape-bagging paper were analyzed. Results showed that air-permeability and transmitted light of grape-bagging paper were important. It was tried to see the influence of paper structure on air-permeability, transmitted light and the grapes saccharinity. For making different structure of grape-bagging paper, papers were produced with different freeness levels at several pressure conditions. Coloration time of Campbell grape with new bagging paper started about 5 days earlier than that with usual bagging paper, It was also possible to improve the saccharinity about 0.1-N0.8 Brix. Because new bagging paper has a low apparent density, it affected the saccharinity and coloration time of grape.
Development of Antibacterial Corrugating Liner Using Essential Oils Extracted from Chamaecyparis obtusa
Journal of Korea Technical Association of The Pulp and Paper Industry, volume 33, issue 3, 2001, Pages 59~68
Essential oils extracted from Chamaecyparis obtusa were applied to make antibacterial corrugating liner. The quantitative analysis of the essential oils was carried out by GC-MS, which showed that the monoterpenes as a basic component of the essential oils extracted from Chamaecyparis obtusa in the domestic mountain were greater in amount than those in China. The antibacterial activity was then examined with Tyromyces palustris and gram-negative/positive bacteria. The papers treated with the essential oils desplayed great resistance against T. Palustris and gram bacteria but the best results were obtained with the handsheet formed by softwood bleached kraft pulp rather than the liner by OCC. The low antibacterial activity of the liner was considered to be due to starch components which could be readily attacked by the fungi.
The Effect of Antibacterial Agent for Candida albicans Inhibition of Diaper Rash
Journal of Korea Technical Association of The Pulp and Paper Industry, volume 33, issue 3, 2001, Pages 69~74
Diaper rash is found on the skin inside of babys diaper area. Most diaper rashes are caused by prolonged contact with the moisture, germs, and ammonia of the stool and urine. Some diaper rashes are caused by fungi infection such as candida albicans and Preteus vulgaris. In this study, Candida albicans was used as a test microorganism and experiment was carried out to inhibit diaper rash. Handsheets were treated with chitosan oligosaccharide, bamboo extractives, as well as mixture of monolaurin as an emulsifier and bamboo extractives. Both shake flask method and halo test were applied in order to examine the antimicrobial activity of each sample. It was found from both results of the halo test and shake flask method that handsheets treated with chitisan oligosaccharide or bamboo extractives showed antimicrobial property. In the treatment of bamboo extractives without emulsifier, no distinct difference in antimicrobial effect was found between bamboo branch and bamboo leaves extractives. In case of mixture of bamboo extractives and emulsifier, the result also suggested that bamboo branch showed better syngergistic effect than bamboo leaves. Both chitosan oligosaccharide and bamboo extractive can be used as antifungal agents against Candida albicans for making diaper.
The Effect of Chemical Pretreatment on Steam Explosion and Oxygen-alkali Pulping of Oak Wood
Journal of Korea Technical Association of The Pulp and Paper Industry, volume 33, issue 3, 2001, Pages 75~83
The potential of oxygen delignification is a powerful tool to reduce detrimental environmental effects. This study was performed to investigate the effect of steam explosion treatment of chemically treated oak wood on oxygen-alkali pulping. Pulp yield during steam explosion treatment by
-NaOH impregnation was higher than the other impregnation chemicals. Also, NaOH extraction at room temperature after steam explosion treatment improved the kappa number from 140~116 to 90~64. Oxygen-alkali pulping of chemical steam explosion treated woods affected to pulp yields.
-NaOH impregnation was very effective to higher carbohydrate yields at same delignification level. Its carbohydrate yield seemed to be highly related to the effluent pH. Oxygen-alkali pulping after steam explosion treatment of
-NaOH impregnated wood was shown that carbohydrate yield was very high because its effluent pH was increase from natural to mild alkali. Even if oxygen bleaching limit the delignification to 50% in order to avoid unacceptable yield and viscosity losses, oxygen-alkali pulping after steam explosion by
-NaOH impregnation was possible to extend the delignification more than 80%. Considering high pulp yield with lower lignin content from steam explosion treated wood, it might be profitable to end the cook at a high kappa number instead of a low kappa number, and continuously apply the oxygen delignification, in order to better quality pulp.
Studies on the Bleaching of Rice-Straw Chemical Pulp (II) -Two-Stages Bleaching-
Journal of Korea Technical Association of The Pulp and Paper Industry, volume 33, issue 3, 2001, Pages 84~99
This study was carried out to acquire basic data necessary for the use of rice-straw chemical pulp. It investigated the proper bleaching conditions when rice-straw chemical pulp(alkaline sulfite-
) was bleached using the various kinds of bleaching agents by the two-stages bleaching methods. And, physical properties of pulps bleached with eight kinds of two-stages bleaching methods were tested. The results of this study were as follow; 1. The first-stage bleaching was conducted under the proper conditions with chlorine(C). And then, the proper conditions related to the calcium chlorite(H), hydrogen peroxide(P) and sodium hydrosulfite(Y) bleaching as the second-stage bleaching were investigated. The proper conditions of CH stage were determined to be 0.3% concentration of calcium chlorite,
of reaction temperature and 20min. of reaction time. For CP stage, the proper conditions of concentration of hydrogen peroxide, reaction temperature and reaction time were 1.5%,
and 90min., respectively. And for CY stage, the proper conditions were 0.5% concentration of sodium hydrosulfite,
of reaction temperature and 90min. of reaction time. 2. The first-stage bleaching was conducted under the proper conditions with chlorine dioxide(D). And then, the proper conditions related to the calcium chlorite(H), hydrogen peroxide(P) and sodium hydrosulfite(Y) bleaching as the second-stage bleaching were investigated. The proper conditions of DH stage were determined to be 0.5% concentration of calcium chlorite,
of reaction temperature and 5min. of reaction time. For DP stage, the proper conditions of concentration of hydrogen peroxide, reaction temperature and reaction time were 1.0%,
and 90min., respectively. And for DY stage, the proper conditions were 0.3% concentration of sodium hydrosulfite,
of reaction temperature and 20min. of reaction time. 3. The first-stage bleaching was conducted under the proper conditions with calcium chlorite(H). kAnd then, the proper conditions related to the hydrogen peroxide(P) and sodium hydrosulfite(Y) bleaching as the second-stage bleaching were investigated. The proper conditions of HP stage were determined to be 0.3% concentration of hydrogen peroxide,
of reaction temperature and 60min. of reaction time. For HY stage, the proper conditions of concentration of sodium hydrosulfite, reaction temperature and reaction time were 2.5%,
and 30min., respectively. 4. When the rice-straw chemical pulps were bleached with eight kinds of two-stages bleaching methods in the proper conditions mentioned above, respectively, the final brightnesses after CH, CP, CY, DH, DP, DY, HP, and HY bleachings were 62.0, 74.3, 61.4, 58.9, 66.9, 62.9, 50.4 and 60.1, respectively. And strengthes of pulps bleached with DP and DH methods were comparatively higher than those of pulps bleached with other bleaching methods.