• 펄프종이기술
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• 제42권2호
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• pp.61-66
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• 2010

Corn stalk, one of the most abundant agricultural residue in the world, was examined in this study to use it as an alternative fiber source of wood fiber. In order to find the proper way to utilize corn stalk more efficiently, the morphological properties and the papermaking properties of the, bast fibers and the corn pith, were evaluated respectively. Although the bast fiber fraction showed comparable properties to those for hardwoods in the fiber properties and the papermaking properties, the pith resulted in low brightness and low drainage rate. But the short and flexible fibers in pith fraction led to dense and compact handsheet structure, correspondingly the higher sheet strength. There big differences in properties between bast fiber and pith should be considered for the fully utilization of corn stalk.

• 펄프종이기술
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• 제33권4호
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• pp.28-34
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• 2001

Korea traditional handmade paper, Hanji, has been known for more than thousand years for its high strength, high whiteness, high gloss, good ink reception and long lasting quality. Main component fiber of the Hanji is called 'Dak', which is the bast fiber of the Korea paper mulberry ($\textit{Broussonetia kazinoki}$). Dak has long fiber length, and high cellulose DP, if processed properly. The quality of Hanji is partly from the superior quality of Dak over wood fiber, and partly from the traditional papermaking process. The traditional papermaking process includes pulping, bleaching, refining, use of natural polymer, and sheet making process. Every traditional process has its special role. Comparisons between the modern papermaking technology and the traditional process were made in this study. The traditional process effectively protected cellulose DP in pulping and bleaching process, protected fiber length in refining process, and developed the high strength in the sheet forming process over the modern papermaking process.

• Journal of the Korean Wood Science and Technology
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• 제46권2호
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• pp.118-124
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• 2018

Juglans mandshurica is a fast growing hard species, which is a tree in family of Juglandaceae and has a wide distribution in China, Korea and eastern Russia. Plant materials from J. mandshurica have extensively been used in folk medicines to prevent or cure gastric, esophageal, lung and cardiac cancer. As one chain of our searching for anticomplementary agents from natural sources, two epimeric ellagitannins, [2,3-O-4,4',5,5',6,6',-hexahydroxydiphenoyl (HHDP))-(${\alpha},{\beta}$)-D-glucose] (I) and pedunculagin (II) were purified from 70% acetone extracts of the stem barks of J. mandshurica by Thin Layer Chromatography and Sephadex LH-20 column chromatography approaches. The chemical structures of the isolated compounds were characterized by MS, NMR, and a careful comparation with published literatures. The epimeric ellagitannins I and II exhibited inhibitory properties against a classical pathway of complementary system with 50 % inhibitory concentrations ($IC_{50}$) values of 65.3 and $47.7{\mu}M$, respectively, comparing with riliroside ($IC_{50}=104{\mu}M$) and rosmarinic acid ($IC_{50}=182{\mu}M$), which were used as positive controls. Thus, the work indicated both the two secondary metabolites possess excellent inhibitory activity and might be developed as potential anticomplementary chemicals.

• 펄프종이기술
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• 제48권2호
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• pp.56-60
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• 2016

Neutral or alkaline papermaking provides many advantages in paper strength and processing conditions. It also provides the opportunity of using calcium carbonate fillers in papermaking. These diverse advantages have made almost all paper machines of printing and writing papers run under neutral and alkaline conditions. On the other hand, linerboard machines, which use recycled papers as a raw material, are running under acid conditions using a rosin sizing system. Because the recycled raw materials used by the linerboard industry contain significant amounts of alkaline papers, the linerboard industry has an interest in the possibility of using the neutral or alkaline papermaking opportunity. In this study, the compatibility of the recycled linerboards under neutral or alkaline papermaking conditions was examined by recycling them under various pH conditions. The sizing degree of the papers recycled under neutral or alkaline was significantly lower than that of acid formed papers indicating that during the neutral or alkaline recycling process the rosin sized papers lost their sizing efficiency. Recycling of acid formed linerboards under neutral or alkaline conditions increased the amount of foam, and the foam contained substantial amount of solid materials derived from the acid sizing systems. Use of cationic polyelectrolytes including PEI and poly-DADMAC improved the sizing degree of the recycled papers under neutral and alkaline conditions. PEI decreased the foam generation as well while poly-DADMAC did not show any reducing effect of the foam. These results suggest that PEI forms coordinate bonds with rosin acid and precipitate them onto the surface of recycled fibers, while the reaction products between poly-DADMAC and rosin acid ions still remain water soluble under neutral or alkaline conditions.

• 한국펄프종이공학회:학술대회논문집
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• 한국펄프종이공학회 2004년도 춘계학술발표논문집
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• pp.56-65
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• 2004

The Asia Pacific papermaking giants are China, Japan and Korea followed by Indonesia. The strong trends in recent years have been the move to alkaline/neutral sizing which has assisted the move from kaolin and talc as the major filler minerals to ground calcium carbonate and precipitated calcium carbonate. Kaolin remains important as a constituent in many coating formulations and Chinese-sourced talc, due to its brightness and price will remain important especially in paper filler minerals. The need for ever increasing printing surface quality and continuing efforts by the paper manufacturers to keep costs under control will ensure minerals in papermaking will continue to be a dynamic subject in the years ahead.

• 펄프종이기술
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• 제33권2호
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• pp.1-7
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• 2001

Use of high yield pulp and recycled fiber as raw materials and water system closure result in higher fines content and buildup of organic and inorganic contaminants in white water. These are detrimental for the effectiveness of chemical additives including retention aids. Thus it is imperative to employ a retention systems that maintains its efficiency in closed papermaking system for reducing fresh water consumption. The performance of four different microparticle retention systems including cationic polyacrylamide (C-PAM)/bentonite, highly charged cationic starch (HCS)/silica, C-PAM/micropolymer, cationic guar gum (CGG)/silica was evaluated and compared at three different levels of papermaking system closure. Buildup of detrimental substances in a closed white water system increased cationic demand and finally reduced the performance of retention systems. Cationic starch and guar gums maintained their effectiveness in retention in closed white water systems contaminated with anionic trashes because of their structural rigidity and hydrogen bonding ability. Particularly, cationic guar gums, due its stiffness of molecular structure, appeared perform better than catinonic starch.

• Journal of the Korean Wood Science and Technology
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• 제26권2호
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• pp.51-58
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• 1998

Structural changes of cellulosic fibres during the papermaking process were studied by analysis of FTIR spectra collected by the transmission method. The spectra were obtained from a carefully prepared handsheet, using a special infra-red (IR) cell suitable for evacuating the sample. The deconvolution technique was also applied for sharpening the FTIR spectra in the frequency range of the OH and CH stretching bands, which gave detailed information on the structural changes of cellulose. The intensity of some bands was decreased by predrying the sample as a result of the removal of adsorbed moisture. An increase in intensity of some bands in the frequency range of 3700 to $3200cm^{-1}$ was shown at a higher beating level. This increase in intensity was caused by changes in the crystal domain of cellulose resulting from the exposure of the crystalline area on the fibre surface.

• 한국펄프종이공학회:학술대회논문집
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• 한국펄프종이공학회 2006년도 PAN PACIFIC CONFERENCE vol.1
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• pp.67-71
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• 2006

Strong oxidizing biocides are commonly used to control biofilm formation in alkaline papermaking systems. However, paper streams contain many substances that react with or consume oxidizers (e.g., fiber and starch, Therefore, to achieve effective microbiological control, the oxidizer must be overfed to overcome the effect of these substances. When dosed in this manner, the oxidizer can cause many unwanted reactions and adverse side effects, including the consumption of costly papermaking additives increased corrosion rates, and reduced felt life. Some oxidizers also contribute to the formation of halogenated organic compounds. When used for biofilm control, strong oxidizers can cause more problems than they remedy. A patented biocide that effectively controls biofilm without the adverse side effects associated with strong oxidizing biocides is available from Hercules. $Spectrum^{(R)}$ XD3899 Ammonium Bromide Technology, which can be described as a mild oxidizer, is currently used on more than 300 machines globally and has resulted in numerous production and/or machine efficiency records since its introduction in 2001.

• 펄프종이기술
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• 제31권1호
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• pp.52-60
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• 1999

Drainage rate in wet-end, which has significant influences on the production capacity, product quality and process economics in papermaking, becomes an important factor in the modern high speed papermaking processes owing to increased level of fines contained in today's pulp materials and increased papermaking system closure. A study was carred out to investigate the influence of beating and fines content on natural and vacuum dewatering using a vacuum drainage tester. Increase in beating and accumulation of fines in the stock decreased natural dewatering, Vacuum dewatering effect, however, increased substantially as beating and fines content were increased. But this increase in vacuum dewatering decreased again when a stock is severely beaten or fines content is greater than 35%. Above this level of fines content, mobile fines migrates to the interstices of the forming web to cause sealing or plugging which restrict fluid movement through the web.

• 한국펄프종이공학회:학술대회논문집
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• 한국펄프종이공학회 1999년도 Proceedings of Pre-symposium of the 10th ISWPC
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• pp.125-129
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• 1999

This paper dealt with effect of dual component and micropartical retention system on papermaking. First-pass retention under dynamic drainage condition was studied in neutral and alkaline papermaking system. Cationic starches, amphoteric starches and amphoteric polyacrylamide were added prior to high shear force, then anionic. The system is found to be very useful to inprove filler retention. For mitigating unfavorable effect of interfering sub-stances, anionic trash catcher(ATC) such as p-DADMAC was tested in this study.