• 펄프종이기술
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• 제36권1호
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• pp.16-23
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• 2004

Recently the increased concerns about the cost reduction and environmental protection make the paper industry increase the closure level of papermaking system, which results in the buildup of organic and inorganic materials in the papermaking process water. Increase of the system closure causes deterioration of additive performance and provokes diverse problems in papermaking process and product quality. To investigate the effects of process water quality on the physical properties of fine papers handsheets were prepared with process water containing various amounts of inorganic and organic contaminants including calcium or sodium ions and oxidized or cationic starches. Inorgainc and organic materials did not show any significant effect on the physical properties of handsheets. Recycled GCC showed the same trends as inorganic and organic materials. The performance of cationic starch was deteriorated, however, in the recycled white water, which resulted in the reduction of tensile index of handsheets.

• 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.

• Journal of Microbiology and Biotechnology
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• 제33권2호
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• pp.151-166
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• 2023

Yeast extract is a product prepared mainly from waste brewer's yeast, which is rich in nucleotides, proteins, amino acids, sugars and a variety of trace elements, and has the advantages of low production cost and abundant supply of raw material. Consequently, yeast extracts are widely used in various fields as animal feed additives, food flavoring agents and additives, cosmetic supplements, and microbial fermentation media; however, their full potential has not yet been realized. To improve understanding of current research knowledge, this review summarizes the ingredients, production technology, and applications of yeast extracts, and discusses the relationship between their properties and applications. Developmental trends and future prospects of yeast extract are also previewed, with the aim of providing a theoretical basis for the development and expansion of future applications.

• 펄프종이기술
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• 제43권4호
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• pp.23-30
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• 2011

Fillers have been used for papermaking in order to enhance the optical properties, to improve sheet formation, printability and dimensional stability and to reduce the furnish cost. However, filler particles in paper interfere with fiber-fiber bonding, resulting in decreased paper strength. In order to increase filler content in paper without sacrificing too much paper strength, dual addition technology of fillers was investigated. As a first step, the effects of thick stock addition of fillers on paper properties and papermaking process were elucidated. It was shown that thick stock addition of fillers could increase paper strength at a given filler content. No significant adverse effects on formation, drainage and filler retention were observed. However, bulk of paper was reduced with thick stock addition of fillers, which shall be resolved with regulating other factors such as the mixing ratio of pulps and type of fillers.

• 한국펄프종이공학회:학술대회논문집
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• 한국펄프종이공학회 2007년도 추계학술발표논문집
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• pp.127-134
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• 2007

Paper is composed network of fibers. Since paper is plain, most cases paper is considered two-dimensional. But network of fibers creates a network of pores, and pores between fibers are most important part of the paper structure. So we have to make an approach to the paper by three-dimensionally. Pore structure in the Z-direction of the paper can affect directly not only basic properties od the paper such as density, porosity, opacity and strength but also coverage of the coating colors during coatong and printing properties. We studied effect of raw materials of the papermaking and physical treatment on the pore structure and properties of the paper.

• 펄프종이기술
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• 제46권4호
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• pp.1-10
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• 2014

In papermaking industry, inorganic fillers are widely used for the purpose of improving opacity, brightness, printability, uniformity and dimensional stability. They are also useful for production costs and energy savings. In the past, inorganic fillers in papermaking industry only focused on micro-scale but recently, new trials on nano-powdered technology are applying. Even nano-powdered fillers are rapidly utilized for improving the optical and surface properties in coating and surface sizing, there still have some problems in wet-end process due to poor dispersibility and retention. In this study, nano-particled calcium carbonate was produced by milling the PCC and its applicability between micro sized and nano sized calcium carbonated was compared in wet-end process, and finally the sheet properties were evaluated. Nano-PCC was not retained in sheet structure without applying retention system, but with retention system nano-powdered PCC was absorbed on fiber surface with expanding the fiber networks. The application of PAM-bentonite system has resulted in high ash retention and bulky structure for copier paper, and good optical properties in brightness and opacity. However, it required to solve the weakness of low tensile property due to interruption of hydrogen bonding by nano fillers.

• 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.

• 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.

• 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.

• 펄프종이기술
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• 제36권4호
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• pp.16-24
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• 2004

The reduction of paper machine water usage is precursor to the water system closure of any mills. This reduction in water consumption reduces the loss of solids; especially fine particulates and their surface adsorbed chemical additives, from mills, which causes an inevitable increase of fine materials in papermaking systems. Also the reduction of paper machine water usage causes substantial increase of organic and inorganic substances in process water. The deterioration of the papermaking process water quality accompanying the reduction of papermaking system closure can be a prime source of the aggravation of paper quality and process efficiency. It is of great importance for paper mills to investigate the influence of the level of papermaking system closure on the paper properties and process runnabililty before implementing process closure. To predict the changes in paper properties at different levels of system closure, highly cotaminated white water was prepared using reverse osmosis technology and used to prepare handsheets from fine paper and newsprint stocks. Results showed that the quality of process water affects the strength. Preparation of highly contaminated process water and handsheet forming with headbox stocks provided important criteria to determine the relationship between the qualities of process water and paper products.