• Journal of the Korean Graphic Arts Communication Society
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• v.30 no.3
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• pp.35-43
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• 2012

Internal bonding strength of printing paper was increased with sea-algae pulp treatment. Spacially, 9% contents sea-algae pulp treatment in the hardwood pulp are more effective than in the softwood pulp. Most effective mixture ratio of the raw matrials for improvement of the internal bonding strength are softwood pulp 30%, hardwood pulp 70%, sea-algae pulp 9%. Internal bonding strength is effective in more sea-algae pulp contents and softwood pulp contents and wetness.

• Journal of Korea Technical Association of The Pulp and Paper Industry
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• v.31 no.3
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• pp.77-82
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• 1999

The delignification, and optical and strength properties were determined to compare the ozone treatment effect in hardwood and softwood CTMPs. During ozone treatment, the delignificantion was much higher in hardwood pulp than in softwood pulp . The optical and strength properties which were very dependent upon the lignin content in pulp were significantly improved in the case of hardwood pulp . The ozone treatment of high yield pulp was more effective in hardwood pulp than that of softwood pulp.

• Proceedings of the Korea Technical Association of the Pulp and Paper Industry Conference
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• 1999.04b
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• pp.232-238
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• 1999

The reinforcement of wheat straw pulp sheets with softwood kraft was studied, with special emphasis on the impact of softwood kraft beating and the proportion softwood kraft in straw pulp. the reinforcement was evaluated by measuring the tensile stiffness sand in-plane fracture behavior of samples. the results were compared with a mechanical pulp (TMP) and with a hardwood birch kraft, both reinforced with the same softwood kraft. Wheat straw pulp forms strong interfiber bonds. Therefore, its tensile stiffness and tensile strength are larger than TMP used. In-plane tear tests showed that a pure wheat straw pulp sheet has low fracture energy and correspondingly a narrow fracture process zone. The fracture energy of the reinforced straw sheets was found to increase linearly with the proportion of both unbeaten and beaten softwood pulps.

• Journal of Korea Technical Association of The Pulp and Paper Industry
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• v.34 no.3
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• pp.25-31
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• 2002

The purpose of this study was to analyze how the fiber properties and mixing ratio of softwood and hardwood pulp affect on roundness of printed image. Softwood pulp and hardwood pulp were refined to 400 and 600ml CSF by Valley beater and handsheets of 70 g/$m^2$ basis weight were made at different mixing ratios of hardwood and softwood pulp. The roundness, dot area, and shape of the printed dot were measured by Image Analyzer. The depths and shapes of the acridine orange penetration into paper were measured by CLSM. With higher mixing ratio of hardwood pulp, the paper showed higher air-permeability and better formation, especially at lower freeness. The roundness of the printed image became better and the dot size became smaller when the amount of hardwood pulp increased. Penetration depth of acridine orange by CLSM became greater and roundness increased to real circle when the amount of hardwood pulp increased. It was thought that higher mixing ratio of hardwood fibers resulted in efficient penetration by better formation with uniform micro-pore distribution and it increased roundness. It was thought that fiber properties and mixing ratio affected the structure of paper and the shape of the printed dot. This study showed that the measurement of depth of the liquid penetration into paper without destruction and contact was feasible. Moreover, this method showed that the shape of the liquid penetration was measurable.

• Journal of Korea Technical Association of The Pulp and Paper Industry
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• v.43 no.4
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• pp.1-10
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• 2011

Beating or refining is an energy intensive process in paper industry. In India, most of the paper industries blend long fibered softwood pulps with short fibered hardwood or agro based pulps to get the paper properties of competitive level. Refining characteristics of the blend of pulps is very crucial with respect to freeness and strength properties. This study has been carried out to understand the refining behavior of three hardwood pulps and a softwood pulp. The hardwood and softwood pulps are blended in different proportions in two different ways; a) blending after their separate refining, and b) blending before refining followed by mixed refining of the blended pulps. Freeness of pulp, strength, optical and surface properties of paper along with formation have been determined and compared for both the refining methods. The fiber classification of refined pulps was also carried out to analyze the effect of refining method on fiber morphology. The mixed refining of hardwood and softwood pulps marginally affects the fiber morphology in comparison to separate refining of pulps. The strength and other properties of paper prepared from mixed refining of pulps are either better or comparable than those of separately refined pulps.

• Journal of the Korean Graphic Arts Communication Society
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• v.29 no.1
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• pp.89-99
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• 2011

The making of high leveled smoothness for the printed electronics base paper, wood pulp and sea algal pulp were mixed. If sea algal pulp contents is increased to 9%, the smoothness was moderately increased, and more effective in Softwood mixture than Hardwood, low freeness(high wetness) than high freeness(low wetness).

• Journal of Korea Technical Association of The Pulp and Paper Industry
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• v.43 no.3
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• pp.106-112
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• 2011

The effects of alkaline treatment on the WRV, crystalline structure and sheet structure of softwood and hardwood bleached kraft pulp were investigated. Sodium hydroxide and sodium carbonate were used as chemicals for alkaline treatment and two levels of alkali dosage (5%, 10%) were applied respectively. Alkali treated and untreated pulp were refined to three levels (550, 450 and 350 mL CSF). WRV of the alkali treated pulps depended on the alkaline type and concentration. It was found that the crystalline structures of softwood and hardwood pulp were not changed by refining. Sodium carbonate and lower concentration of sodium hydroxide treatment did not caused any modification of cellulose crystalline structure, while higher concentration of sodium hydroxide treatment caused the partial modification of cellulose crystalline structure. Alkaline treatment of hardwood bleached kraft pulp led to the shrinkage of fiber diameter and bulky structure of sheet. Alkaline treatment of softwood bleached kraft pulp did not cause the significant change in fiber shrinkage and bulk of sheet.

• Journal of Korea Technical Association of The Pulp and Paper Industry
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• v.33 no.3
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• pp.1-8
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• 2001

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.

• Journal of the Korean Wood Science and Technology
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• v.35 no.6
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• pp.166-174
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• 2007

To know the effect of enzymatic pre-treatment on softwood Kraft pulp, two xylanse-encoding genes, named xynl and xynll were isolated from Thrichoderma ressei. Structural genes of xylanase (XYNI, XYNII) and cellulase (EGIV-CBDII) were isolated from T. ressei and Rumicoccus albus respectively, and expressed in E. coli. bacterial culture. The specific activity of purified recombinant XYNI is higher than XYNII. The brightness of XYNI treated softwood Kraft pulp increased to 29.9%. On further sequential treatment with EGIV-CBDII and XYNI the brightness of softwood Kraft pulp were improved to 9.1 and 73% respectively. As expected the Kappa number of softwood Kraft pulp also decreased 8.1, 4.6 and 3.2% respectively. Results further indicate that this sequential combination of enzyme treatment has synergic effect for improving bleaching of softwood Kraft pulp.

• Journal of Korea Technical Association of The Pulp and Paper Industry
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• v.33 no.1
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• pp.30-37
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• 2001

The effects of enzymatic treatment of recycled fiber were investigated to obtain the basic informations which can be used to improve the papermaking properties of recycled fiber. The recycled fibers were prepared by the repeated handsheet making and disintegrating of hardwood of hardwood and softwood kraft pulp. Novozym 342, Dinimax and Pulpzyme HC were used for enzymatic treatment. The change of fiber length distribution, freeness, contact angle and crystallinity of pulp were measured. The brightness, opacity, breaking and tear index of paper were also measured. The enzymatic treatment decreased long fiber fraction of recycled hardwood fiber, but increased long fiber fraction of recycled softwood fiber. Freeness was decreased with 0.1% enzyme and then increased again with the increase of th enzyme dosage. The improvement of flexibility of recycled fiber was obtained through the decrease of contact angle that is resulted from the decrease of crystallinity of fiber. Brightness and opacity were affected by the type of pulp and enzyme, and dosage of enzyme. Breaking length of recycled hardwood fiber was improved with enzyme treatment, but breaking length of recycled softwood fiber was decreased except for 0.01% Pulpzyme treatment. Tear index was decreased with enzymatic treatment and the lowest decrease was observed with the treatment to Pulpzyme.