• 한국펄프종이공학회:학술대회논문집
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• 한국펄프종이공학회 2006년도 PAN PACIFIC CONFERENCE vol.2
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• pp.181-190
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• 2006

This study was conducted to develop dry forming technology and evaluate the properties of dry formed paper made from Hw-BKP. A dry forming mold (DFM) was developed to observe the phenomena of dry forming and evaluate the properties of formed papers. To upgrade the DFM a dry forming system (DFS) was developed. This DFS was designed to improve the formation of dry formed papers and enhance the productivity of dry forming. Dry forming gave papers with greater bulk and opacity than wet forming. Tensile strength of dry formed paper was greater than that of conventional wet formed handsheet when they were made from the same dry disintegrated fibers. But tensile strength of conventional wet formed handsheet made from beaten fiber was much greater than that of dry formed paper made from dry disintegrated fibers. When solvent dried beaten fibers were used in dry forming, the tensile strength of dry formed papers reached 73.5% of the wet formed handsheets made from beaten fiber. It showed that dry forming has a significant potential in improving strength properties when proper preparation of fibers and appropriate humidification, pressing, and drying processes are employed.

• 펄프종이기술
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• 제39권2호
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• pp.1-8
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• 2007

To examine the feasibility of dry forming technology for papermaking, a dry forming mold (DFM) was developed and evaluated. Main fanning section of DFM was a cylindrical tube, and at the top of the mold a stirring equipment was placed to disperse dry fibers. These fibers were screened using a hole type screen plate placed just under the stirring equipment and dropped freely on the fanning wire located 0.9 m below of the screen plate to form a dry fiber pad. The vertical and horizontal velocity of air flow in the forming cylinder were evaluated and analyzed to find the most effective method of air flow control in the cylinder. Humidification and pressing conditions to obtain a decent dry fanned papers were examined. Results showed dry fanned papers can be prepared with this dry forming mold. And this mold can be used to examine the effect of the papermaking process factors including pressing pressure, drying temperature, humidification on sheet quality of dry formed papers.

• 펄프종이기술
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• 제42권3호
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• pp.50-57
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• 2010

A mill trial was performed in a kraft paper mill in order to evaluate the possibility of utilizing dual polymer dry strength aids system consisting of cationic PVAm and anionic PAM. It was found that the cationic PVAm - anionic PAM dry strength additives can improve paper strength without significantly disturbing the stability of the kraft papermaking process when virgin UKP was used as a furnish. Tensile strength (25.3% in machine direction, 48.4% in cross machine direction), elongation of paper (31.6%, 15.6%) and tensile energy absorption (48%, 54%) were improved. Air permeability of the kraft paper was improved as well (22%). Tear strength was decreased with PVAm dry strength aids system, but it can be compensated with decreasing refining degree. In addition, the mill trial results indicate that highly air permeable kraft sack paper can be produced by the addition of PVAm dry strength agents at the stock with reduced freeness.

• 펄프종이기술
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• 제41권1호
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• pp.9-16
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• 2009

Cylindrical dry forming mould was developed to carry out a feasibility study of dry forming of papers. The effect of disintegration, forming, humidification and pressing on dry formed papers was examined. Dry disintegrated fibers showed the similar fiber length distribution to wet disintegrated fibers, but they showed distorsion and damaged appearance on the surface. Process parameters required to form a uniform fiber pad was investigated. A proper screening and air dispersion method was selected that gives proper formation. Humidification and pressing conditions were examined to get a good dry formed papers in dry forming. Results showed that dry forming method can be used to make a sheets with reasonable formation and properties.

• 한국염색가공학회지
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• 제2권3호
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• pp.43-50
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• 1990

The purpose of this paper is to investigate the dyes solubility of dry cleaning solvents among the current domestic products. The dyes were experimented in following way; 1) The flow rate of dyes by paper chromatography method. 2) The color difference & the absorbance of solvents between the dyed fabrics before and after dry cleaning. From the experiment, following results were obtained. 1. In paper chromatography methods, the flow rate of dyes in the disperse dyes was bigger while flow was not shown in the direct dyes & acid dyes. 2. The more the number of times on dry cleaning in dyed fabrics was, the higher the absorbance of solvents was shown. The results were showed following order, PerchloroethyleneHydrocarbon> Fluorocabon. 3. The color difference between before & after dry cleaning on dyed fabrics showed bigger in disperse dyes.

• 펄프종이기술
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• 제37권4호통권112호
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• pp.26-31
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• 2005

The purpose of this study was to confirm paper strengthening properties with recently commercialized polyvinylamine. Because of its high cationic charge density, polyvinylamine has been investigated as a size retention and surface coating aids. In this study, we tried to confirm polyvinylamine as wet-end additives to improve dry and wet strength using LBKP and BCTMP pulps. As a result, we found improvement of dry and wet tensile properties of polyvinylamine with BCTMP were much better than LBKP condition. This phenomena could be explained that ionic bonding of cationic charge of polyvinylamine with abundant anionic substances of BCTMP was a very important factor to improve dry and wet strength of paper.

• 한국펄프종이공학회:학술대회논문집
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• 한국펄프종이공학회 1999년도 Proceedings of Pre-symposium of the 10th ISWPC
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• pp.186-191
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• 1999

Results are shown on the preparation and characterization of homopolymer of 2-methacryloyloxyethyl isocyanate(MOI) ad copolymers of MOI with styrene synthesized by radical polymerization. The significant effectiveness of the polymers as additives for paper dry and wet strength was found. Dry strength can be increased by 75% and wet strength retention of sheets can reach 30% based on the increased dry strength and about 50% based on the dry strength of untreated sheet. Based on isocyanate group consumption, copolymers containing less isocyanate can give better effect than homopolymer in sheet wet strength improvement. Furthermore, the base paper containing a small amount of polyallylamine hydrochloride was used for polymer treatment and got higher wet strength improvement.

• Archives of Pharmacal Research
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• 제16권3호
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• pp.227-230
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• 1993

A new device to detect methamphetamine (MA), amphetamine(A) and its metabolites in urine was developed using the paper strip method and the test tube method of dry chemical reagents. The reagent containing tetrabromophenolphthalein ethyl ester (TBPE) and borax. For the TBPE paper strip method, a device was prepared with a window at each end of the reagent paper strip ; one window is for the sample application, and the other window is for the methylene chloride. The diffused sample from one window reacts with reagent in the paper and produces color at the point where it meets with methylene chloride which has diffused form the other side. A positive smaple produces as red-purple color and the negative sample a greenish color, with a detection limit of 5-10 ppm. The result can be obtained within one minute. For the TBPE test tube method which contains dry reagents, the detection limit is 5 ppm and the result can be obtaineed within 30 seconds, however the carry-on is not as convenient as the paper strip method. The performance of both methods were evlauated by comparing with the results of gas chromatography (GC) and fluorescence polarizaiton immunoassay (FPIA). The results were proven that both methods were useful as primary screening reagents to detect MA in urine and in dry powder.

• 펄프종이기술
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• 제47권5호
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• pp.127-133
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• 2015

Recent worldwide trends are to develop the environmental friendly chemicals and processes in order to reduce the global warming and climate change phenomena. One of similar efforts in paper industry is to substitute the petroleum-based SBR latex by starch-based biobinder. The disadvantage of biobinder found through laboratory scale study was the lower dry pick strength than SBR latex. The objective of this study is to confirm the substitutability of SBR latex with biobinder through mill trial. Although biobinder itself gave lower dry pick strength, it was found that the use of SBR latex and biobinder mixture (50:50) could improve the dry pick strength. The introduction of biobinder into coating binder system improved the opacity of coated paper. Optical properties (brightness and whiteness), ink trapping, print gloss and mottling level of paper coated with biobinder system were similar to those of SBR latex.

• 조명전기설비학회논문지
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• 제24권8호
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• pp.142-149
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• 2010

본 논문은 준평등전계에서 뇌임펄스전압에 대한 $SF_6$와 dry-air의 절연파괴 특성에 대하여 기술하였다. 준평등전계로 사용된 구-평판전극계의 전계이용률은 71[%]이다. $SF_6$는 0.1~0.2[MPa] 범위에서, dry-air는 0.2~0.6[MPa]에서 $SF_6$와 dry-air의 절연파괴전압을 임펄스전압의 극성과 가스압력에 따라 측정 분석하였다. 그 결과 뇌임펄스전압에 대한 두 가스의 절연파괴전압은 정극성이 부극성보다 높았으며, $SF_6$의 절연파괴전압이 dry-air의 절연파괴전압보다 약 2.67배정도 높았다. 본 연구결과는 뇌서지에 대하여 우수한 성능을 가지는 배전기기에서 $SF_6$의 대체가스 성능 평가에 유용한 정보가 될 것이다.