도시 폐휴지의 질산 펄프제조와 펄프폐액의 입상 비료화 기술개발(I) -폐골판지 상자(OCC)의 질산 펄프제조 조건-

임기표,위승곤,김창래,양정훈 한국펄프종이공학회 2000 펄프.종이기술 Vol.32 No.4

A series of studies on nitric-acid pulping of municipal recycled waste papers were carried out to substitute the bleached chemical pulp imported for producing printing paper as well as to use its solidified spent-liquor as fertilizer. The first experiment was carried out to find the optimum treatment conditions such as pulp consistency, nitric acid charge and temperature in $HNO_3$-alkali pulping process. The results obtained were as follows: 1. Some selective delignification of OCC pulp was conducted by $HNO_3$-alkali process. The higher the temperature and concentration of nitric acid, the lower the pulp yield and kappa number of treated pulp. while its brightness was increased. 2. The higher consistency required the stronger mixing in case of more than 5% pulp. 3. In the laboratory, the suitable $HNO_3$-treating condition seemed to be less than 6% consistency, lower than 500% $HNO_3$charge on pulp and lower than $100^{\circ}C$ in cooking temperature. 4. The spent liquor with 1.77% N-content seemed to be slow-release nitrogen fertilizer suitable for agriculture.

효소를 이용한 크라프트펄프의 무감소표백(제2보) -소나무 크라프트펄프-

강진하,박성종,정인수 한국펄프종이공학회 1998 펄프.종이기술 Vol.30 No.3

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.

박테리아 셀룰로오스의 첨가가 화학열기계펄프의 종이물성에 미치는 영향

조남석,최태호,서원성 한국펄프종이공학회 1998 펄프.종이기술 Vol.30 No.4

The bacterial cellulose(BC) has many unique properties that are potentially and commercially beneficial. In order to enhance inherently inferior physical property of chemithermomechanical pulp(CTMP) sheet, chemical pulp has been used widely. Bacterial cellulose also has an enhanced sheet strength because of its unique physical and morphological features. This study was carried out to inverstigate the effect of BC addition on physical properties of CTMP sheets. The effect of BC addition on its optical properties was also discussed. The apparent density, internal bond strength, Young's modulus, tensile strength and folding endurance of CTMP sheet are increasing with increase of BC contents. This strength increase would be attributed to the increase of relative bonding sites among pulp fibers by addition of BC which has microfibrillar structure with very high specific surface areas. There were not so significant changes in opacity of CTMP sheet upto 20% addition level of BC, while over 40% addition, the opacity gradually decreased and levelled off. Porosity is decreased with addition of BC. This decrease would be attributed to densification of sheet by fine and filamentous structure of BC fibers.

활엽수크라프트펄프 및 박테리아 셀룰로오스부터 제조한 종이의 물성

조남석,김영신,박종문,민두식,안드레레오노비치 한국펄프종이공학회 1997 펄프.종이기술 Vol.29 No.4

Most cellulose resources come from the higher plants, but bacteria also synthesize same cellulose as in plants. Many scientists have been widely studied on the bacterial cellulose, the process development, manufacturing, even marketing of cellulose fibers. The bacterial celluloses are very different in its physical and morphological structures. These fibers have many unique properties that are potentially and commercially beneficial. The fine fibers can produce a smooth paper with enchanced its strength property. But there gave been few reports on the mechanical properties of the processing of bacterial cellulose into structural materials. This study were performed to elucidate the mechanical properties of sheets prepared from bacterial cellulose. Also reinforcing effect of bacterial cellulose on the conventional pulp paper as well as surface structures by scanning electron microscopy were discussed. Paper made from bacterial cellulose is 10 times much stronger than ordinary chemical pulp sheet, and the mixing of bacterial cellulose has a remarkable reinforcing effect on the papers. Mechanical strengthes were increased with the increase of bacterial cellulose content in the sheet. This strength increase corresponds to the increasing water retention value and sheet density with the increase of bacterial cellulose content. Scanning electron micrographs were shown that fine microfibrills of bacterial celluloses covered on the surfaces of hardwood pulp fibers, and enhanced sheet strength by its intimate fiber bonding.

pH와 첨가제에 의한 이산화염소의 분해율 및 펄프 표백효과(2)-첨가제가 chlorate 생성량의 감소와 펄프 표백 효과에 미치는 영향

윤병호,왕립군 한국펄프종이공학회 1999 펄프.종이기술 Vol.31 No.4

In CLO2 delignification and bleaching process, formation of chlorate corresponds to a loss of 20-36% of the original CKO2 charge. Because chlorate is inactive and harmful to environmental, it will be of benefit to find methods that can reduce the formation of chlorate during chlorine dioxide bleaching. Chlorate is mainly formed by the reaction HCIO +ClO2 $\longrightarrow$H+ + Cl_ +ClO3-2 On the other hand, AOX in chlorine dioxide bleacing is formed also due to the in-situ produced hypochlorous acid. THus both AOX and chlorate could be reduced by addition of hypochlorous acid. Some paper son the reduction of AOX by additives appeared , but systematic data on chlorate reduction as well as pulp and effluent properties are not available. THus this paper of focused on the effects on the reduction of chlorate and chlorine dioxide bleachability. The additives, fulfamic a챵, AMSO, hydrogen peroxide, oxalic acid were found to eliminate chlorine selectively in chlorine and chlorine dioxide mixture.However, when they were added to bleaching process, sulfamic acid and DMSO showed significant reduction of chlorate formation but hydrogen peroxide and oxalic aicd did not, and significant amount ofhydrogen peroxide was found resided in the bleaching effluent , In addition, sulfamic acid and DMSO decreased the bleaching end ph values while hydrogen peroxide and oxalic acid did not, which also indicated that hydrogen peroxide and oxalic acid were ineffective. The difference might be ascribed to the competitives of hypochlorous acid with lignin, chlorite (CKO2) and additives. Sulfamic acid and DMSO showed better pulpbrightness development but less alkaline extraction efficiency than hydrogen peroxide , oxalic acid and control, which means that insitu hypochlorous acid contributes to the formation of new chromophore structures that can be easily eliminated by alkaline extraction. DMSO decreased the delignification ability of chlorine dioxide due to the elimination of hypochlorous acid, but sfulfamic acid did to because the chlroinated sulfamic acid had stable bleachability. In addition, sulfamic acid, and SMSO shwed decreased color and COD of bleaching effluents, hydrogen peroxide decreased effluent color but not COD content, and oxalic acid had no statistically significant effects. No significant decreases of pulp viocosity were found except for hydrogen peroxide. Based on our results , we suggest that the effectiveness of hydrogen peroxide on the reduction of AOX in literature might be explained by other mechanisms not due to the elimination of hypochlorous acid , but to the direct decomposition of AOX by hydrogen peroxide.

효소를 이용한 크라프트펄프의 무감소표백-신갈나무 크라프트펄프-

강진하,박성종,임현아 한국펄프종이공학회 1998 펄프.종이기술 Vol.30 No.1

This study was carried out to bleach the Oakwood kraft pulp without the elemental chlorine using the xylanase or wastewater(We : wastewater enzymes) effluented from the submerged biofilter reactor containing the fungi, Phanerorhaete 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 Oakwood kraft pulps with xylanase, the proper pH, temperature, enzyme dosage and time were 8.0, $35^{\circ}C$ , 400 EXU/kg and 1 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 5.5, $37^{\circ}C$ and 2 hr. respectively. On the other hand, Oakwood 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.

종이의 특성에 영향하는 펄프 섬유특성의 정량적 해석(I)

이강진,박중문 한국펄프종이공학회 1998 펄프.종이기술 Vol.30 No.2

Refining is one of the most important processes of fiber treatment that provides optical and physical properties of final paper products. The evaluation method of refining progress is usually freeness (CSF) or wetness (SR) test because of its rapidity and convenience. However, there are some deficiencies in using freeness or wetness test to evaluate pulp fibers accurately because its results are more influenced by fines contents than extent of fibers treatment. The objective of this study is to show the deficiency of wetness in evaluating the refining process. For this, beating is done by varying the beating load. Handsheets are made after beating until 25 and $32^{\circ}C$ SR, and then paper properties are measured. Refined fibers are analyzed by fiber length, fines contents, curl, kink, WRV, and zero-span tensile strength. The results show that longer beating time is required to reach the same wetness at lower beating load. There are differences in the average fiber length, distribution curve of fiber length, fines contents, curl, kink, WRV of long fiber fraction, drainage time, and zero-span tensile strength of rewetted sample at different beating load. At the low beating load in the same wetness, apparent density, breaking length, burst strength, and tear strength are higher, while opacity and air permeability are lower than those of the high beating load. Using Page s equation, which shows the relationship among tensile strength, intrinsic fiber strength, and interfiber bonding strength, interfiber bonding strength is calculated and analyzed to explain final paper properties. At $25^{\circ}C$ SR, interfiber bonding strength is only slightly higher at 2.5kgf beating load, while the intrinsic fiber strength is substantially higher. At $32^{\circ}C$ SR, intrinsic fiber strength is a little bit higher at 2.5kgf beating load, and interfiber bonding strength is remarkably higher than those of 5.6kgf beating load. These results can be used to explain the different properties of the final paper at selected beating loads.

최신 현미경을 이용한 섬유 및 종이의 성질 분석(제1보)-Confocal Laser Scanning Microscope를 이용한 섬유 밑 종이의 성질 분석-

김철환,Keith Roy Wadhams 한국펄프종이공학회 1998 펄프.종이기술 Vol.30 No.1

With the advent of CLSM in the end of 1980s, it has been applied to the field of pulp and paper science in various ways. This study showed the potentials of CLSM In analyzing a change of pulp fiber and paper properties before and after mechanical treatment. In particular, a quantification of internal fibrillation has been done using cross-sectional images of fibers and image analysis technique, then evaluated the effects of fiber wall delamination on fiber and paper properties. It showed that the delaminated fibers were closely associated to development of the interfiber bonding in a fiber network. The CLSM made it possible to investigate a density profile along the sheet thickness, which was created by some papermaking processes like pressing, drying and calendering. Through the attempt to observe the forming procedure of a fiber network during handsheet making, the CLSM images showed that the pressing stage was considered greatly to contribute to generation of interfiber bonding with removing a free water and partly a bound water between fibers. In addition, the CLSM could be used to illustrate not only a surface profile of paper showing the extent of smoothness or roughness, but also a density profile in a B-direction of the network. Finally it became evident that the CLSM could be used as an excellent tool to predict development in fiber and paper properties before and after mechanical treatment during papermaking processes.

비목재펄프를 이용한 도공원지의 특성이 도공지의 물성 및 인쇄적성에 미치는 영향(I)

임현아,강진하,이용규 한국펄프종이공학회 2000 펄프.종이기술 Vol.32 No.3

This study was carried out to investigate the effect of the type of base papers containing Sw-BDP, HW-BDP and Bamboo-BKP on the properties and printabilities of coated papers. Also it was intended to evaluate the effect of coated paper prepared with anionic and amphoteric latex based coating color. The results obtained from this study were as follows. The fiber length of Bamboo-BKP was observed longer than that of the Hw-BKP and shorter than that of the Sw-BKP. This has effect on physical properties. Therfore the results of mea-suring physical properties were higher ratio of Sw-BKP physical properties tended to be slightly higher with the increase I the mixing ratio. Considering the optical properties of base papers the highest opacity was obtained in case of the Hw-BKP and the second appeared Bamboo-BKP. On the other hand smoothness roughness and air permeability of Bamboo-BKP were lower than those of wood pulp and the optical properties of coated papers tended to show the similar with those of base papers. The ink receptivity and print gloss of the coated papers for Bamboo-BKP were lower than those of wood pulp. As the mixing ratio of Sw-BKP was increased the properties and printabilities were improved slightly. Meanwhile amphoteric latex was improved the optical properties and printability of coated papers.

목질계 Biomass의 변환이용(제1보)-기계펄프로부터 용해용펄프의 제조-

양재경,임부국,이종윤 한국펄프종이공학회 1997 펄프.종이기술 Vol.29 No.3

Dissolving pulp is a low yield(30∼35%) bleached chemical pulp that has a high cellulose content (95% or higher) suitable for use in cellulose derivatives such as rayon, cellulose acetate. This research was studied for dissolving pulp preparation as the raw material of viscose rayon from commertial pulps. (TMP, CP, DIP) In the change of pulp(cellulose) characteristics after sodium hypochlorite and solvolysis treatment. the following results were obtained In the case of sodium hypochlorite pretreatment, we have obtained pulp that high purity cellulose, but degree of polymerization was inclined to decrease less than 170∼240. Comparing sodium hypochlorite pretreatment and solvolysis pretreatment, solvolysis pretreatment is superior to sodium hypochlorite process for making dissolving pulp. We think that the low degree of polymerization of cellulose because of increasing degradation of cellulose during delignification treatment.