• 펄프종이기술
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• 제37권5호통권113호
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• pp.50-55
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• 2005

In previous report, we investigated the impact of hexeneuronic acid and some residual extractiveson lignin determination. These non-lignin components severely interfered lignin content determination which also affect on the oxygen delignification comparison between aspen and pine unbleached kraft pulps. Very different pattern was observed whether based on uncorrected conventional kappa number or based on corrected kappa number in oxygen delignification comparison. Lower kappa number aspen pulps showed poor response to oxygen delignification when kappa number was used as lignin determination method but better response with using the acid lignin method. Phenolic hydroxyl group in kraft pulps were also compared based on uncorrected or corrected kappa numberfor lignin content. Based on uncorrected kappa number, lower kappa number oxygen-delignified pulps had lower phenolic hydroxyl group. However, lower kappa number oxygen-delignified pulps showed much higher phenolic hydroxyl group based on the corrected lignin content. For accurate comparison for residual lignin properties from different pulps, lignin determination should be corrected from non-lignin components contribution to lignin.

• 펄프종이기술
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• 제33권3호
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• pp.37-43
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• 2001

The bleach efficiency between PY and YP bleaching of pulps, which were deinked in neutral (cellulase) and alkaline (NaOH, NaOH/${Na_2}{SiO_3}$) 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.

• 펄프종이기술
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• 제30권3호
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• pp.84-96
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• 1998

This study was carried out to bleach the Pinewood kraft pulp without the elemental chlorine using the xylanase or wastewater(We:wastewater enzymes) effluented from the submerged biofilter reactor containing the fungi, Phanerochaete sordida YK-624. So in this research, the proper treatment conditions(pH, temperature, dosage and time) were investigated respectively. And after the various kinds of multistage bleaching of pulps, the properties of pulps were tested. From the experimental results, we can conclude as follows. In the treatments of Pinewood kraft pulps with xylanase, the proper pH, temperature, enzyme dosage and time were 8.0, $35^{\circ}C, 400EXU/kg and 3 hr. respectively. And in the case of treatment with a wastewater(We) effluented from the submerged biofilter reactor, the proper pH, temperature and time were 5.0, $37^{\circ}C and 3 hr. respectively. On the other hand, Pinewood kraft pulps were bleached by the method of a multistage bleaching using xylanase or We instead of elemental chlorine. Consequently, the strengthes and brightnesses of pulps bleached by the method mentioned above were lower than those of pulp bleached by the conventional method using the elemental chlorine. But it is possible to improve the brightnesses through the increase of chlorine dioxide dosage or use of hydrogen peroxide in the final bleaching stage.

• 한국펄프종이공학회:학술대회논문집
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• 한국펄프종이공학회 2006년도 PAN PACIFIC CONFERENCE vol.2
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• pp.231-237
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• 2006

Grease barrier food containers are commonly used for packaging of fast food, cooked food, and food in general. Greaseproofing is also used for certificate paper and label paper etc. Different pulp raw materials, due to their different fiber morphology and chemical compositions, produce papers of varying characteristics. We used optical photomicroscopy and fiber analysis data to evaluate fiber morphology and traits under various beating conditions in order to understand which pulp raw materials produced superior greaseproofing property when a fluorinated greaseproofing agent was added internally. The experiment studied 9 species of pulps, including 2 softwood (northern pine and radiata pine) bleached kraft pulps which were beaten to 550 and 350 mL CSF, respectively; 3 hardwoods (eucalypts, acacia, mixed Indonesian hardwoods) bleached kraft pulps which were beaten to 450 and 250 mL CSF, respectively; and nonwood fibers of reed, bagasse, and abaca. A fluorinated greaseproofing chemical at 0.12% dosage with respect to dry pulp was added to each pulp preparation and formed handsheets. A total of 67 sets of handsheets were prepared, and their basis weights, thickness, bulks, opacities, wet opacities, air resistance, water absorption and degrees of greaseproofing were measured for an overall evaluation of pulp and freeness on greaseproofing papers. The experimental fiber length, coarseness and distribution characteristics and the greaseproofing results suggest that softwood pulps (radiate pine > northern pine) were superior to hardwood pulps (eucalypts > acacia > mixed Indonesian hardwoods). The unbeaten pulps gave papers with high porosities and nearly devoid of greaseproofing property. Greaseproofing is proportional to air resistance. Among the nonwood fibers, bagasse had the best greaseproofing property, followed by reed and abaca was the poorest. With regards to waterproofing property, hardwood pulps (mixed Indonesian hardwoods > acacia > eucalypts) were better than softwood pulps (northern pine > radiate pine). Among the Nonwood fibers, reed had the highest waterproofing property, and it was followed by abaca, while bagasse had the poorest waterproofing characteristic. In summary, bleached kraft northern pine, eucalypts and reed pulps were best suited for making greaseproofing papers, Freeness of the pulps should be kept at $200{\sim}280mL$ CSF for optimal performance.

• 펄프종이기술
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• 제29권3호
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• pp.34-42
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• 1997

This study was carried out to investigate the proper cooking conditions of soda-anthraquinone and alkaline sulfite-anthraquinone pulping of rice-straw, and get basic data f9r the use of rice-straw chemical pulp through the test of characteristics and physical properties of pulps made in the various cooking conditions From the experimental results , we can conclude as follows. In the soda-anthraquinone pulping of rice-straw, the optimum cooking conditions were 60 min. at $150^{\circ}C$ in the amount of caustic soda of 20% with the addition of anthraquinone(0.05%). And total yield, Kappa No. and brightness of pulp made in the condition above mentioned were 41.9%, 7.7 and 51.1 respectively. In the alkaline sulfite-anthraquinone pulping of rice-straw, the proper mixing ratio of cooking chemical(caustic soda : sodium sulfite) was 50:50. And the optimum cooking conditions were 60 min. at $150^{\circ}C$ in the amount of cooking chemical of 20% with the addition of anthraquinone(0.05%). At that time, the total yield, Kappa No, and brightness of pulp were 50.1%, 9.1 and 40.2 respectively. As a result, the alkaline sulfite-anthraquinone pulping was superior to the soda-anthraquinone pulping in the aspect of yield, but inferior in the viewpoints of Kappa No. and brightness. For the comparison of qualities of pulps made in the various cooking methods and conditions, the physical properties of four sorts of pulps were tested. As a result, soda-anthraquinone pulps were superior to alkaline sulfite-anthraquinone pulps in the various strengths excluding tear strength and brightness. On the other hand, pulps made in the condition of addition of cooking chemical of 20% were superior to pulps in the dosage of 15% in the aspects of all the strengths and brightness.

• 펄프종이기술
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• 제31권4호
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• pp.84-92
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• 1999

Excellence of the Korean traditional paper(Hanji) can be proved by literatures and legacies handed down from generations. However, with the problems pertaining to a majority of traditional manufactures, Hanji industry was declined because of low productivity, insufficient supply of raw material , and reduced demand. therefore, modernizxation of the Hanji technology and development of new uses are very important. This study was carried to investigated the papermaking characteristics of Morus spp.(M.alba, M.Bombycis, and M.Ihou) for new Hanji, modernize manufacturing process of Hanji by grafting on developed modern pulping and papermaking technology, develop the various uses, and establish the foundation for development of high value-added products. Hanji is made from M.Ihou, while stalk , and sulfomethylated pulp gave better sheet formation and higher brightness than those of the others. Physical properties of Hanji which made from bast fiber pulps were better than those of whole stalk pulps. Hanji which made from M.bombycis bast fiber and whole stalk pulps were not so good sheet strength as other species. Sulfomethylated whole stalk pulps were shown better sheet strength than alkali and alkali-hydrogen peroxide whole stalk pulps.

• Korean Chemical Engineering Research
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• 제52권3호
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• pp.335-339
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• 2014

본 연구는 실리카 에어로겔-펄프 복합체의 특성을 조사하였다. Paste 형태의 실리카 에어로겔과 펄프를 혼합하여 복합체를 제조하였으며, SEM 분석을 실시하였다. 또한 임피던스 튜브를 사용하여 흡음률을 측정하였다. 흡음계수의 피크치는 900 Hz 범위에서 얻어졌다. 실리카 에어로겔-펄프 혼합체는 우수한 흡음성능과 복합체의 표면이 소수성을 띠기 때문에 기인하는 내구성 때문에 새로운 흡음제의 가능성이 있다고 사료된다.

• 펄프종이기술
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• 제48권3호
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• pp.73-79
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• 2016

Hexeneuronic acid in soda-anthraquinone(AQ) pulps from Moso bamboo(Phyllostachys pubescebs), Timber bamboo(Phyllostachys bambusoides) and Henon bamboo(Phyllostachys nigra var. henonis) was investigated with mercuric chloride hydrolysis and UV spectroscopic quantification. Concentration of hexeneuronic acid in bamboo pulps was $36.6-45.4{\mu}mol/g$, which contributed to 3.1-3.9 value increase of kappa number. Lower concentration of 4-O-methylglucuronic acid in bamboo xylan contributed to lower hexeneruonic acid content in bamboo pulps than those of hardwood(yellow poplar or eucalyptus) but higher than softwood(red pine).

• 펄프종이기술
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• 제30권2호
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• pp.74-84
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• 1998

This study was carried out to investigate the papermaking characteristics of paper mulberry(Broussonetia kazinoki) for new Korean traditional paper(Hanji). Hanji has been traditionally made only with the bast fiber of paper mulberry. Besides mulberry bast part, wood core was utilized separately or in mixed forms as raw materials for the new Hanji. Hanjis made from the solfomethylated pulp were shown higher brightness and sheet strengths than those from alkali and alkali-hydrogen peroxide pulps. The brightness of solfomethylated pulp was found to be high enough not to need additional bleaching. In the physical properties of the Hanjis mixed with bast part and wood core pulps, the handsheet strengths were decreased as the increase of the wood core pulp contents. But the sheet strengths of Hanjis containing 10∼30% of wood core pulps were higher than those of the Hanji containing bast part pulp only. The sheet formations were improved as the increase of wood core pulp contents, while the sheet strengths were decreased.

• 펄프종이기술
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• 제44권5호
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• pp.63-71
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• 2012

This study was carried out to investigate pulping properties of the forest biomass arising from the national forest management operation. The forest biomass was collected and classified into many groups according to their species and age. After the chips were made from the forest biomass, the measurement of chip size and chemical analysis were performed. To make the pulps from the forest biomass, the kraft pulping was applied and thereafter the physical and optical properties of kraft pulps were measured. The pulp fibers from the forest biomass had the similar mean fiber length, but their properties became different according to wood species and ages. Differently from the other species, kraft pulps from chestnut wood had the highest kappa number. Acacia, paulownia and chestnut woods made kraft pulps with lower tensile strength and brightness than the others. It could be concluded that acacia, paulownia and chestnut woods must be screened out in order to make a good quality of kraft pulps while being collected during Forest Management Operation.