• Journal of the Korean Graphic Arts Communication Society
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• v.14 no.2
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• pp.81-99
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• 1996

The characteristics of printing inks are affected, to a greater or lesser extent, by the size and distribution of the pigment particles in the dispersion. Color strength, transparency and gloss increase with a decrease in particle size of pigments and with an increase in surface area of pigments. On the contrary, opacity and lightfastness tend to increases with an increase in particle size of pigments and with a decrease in surface are and particle size if pigments on the physical properties of printing ink which made up vehicles for sheet fed and organic pigment Lake Red C(C.I Pigment Red 53:1) that different surface area and particle size.

• Journal of the Korean Graphic Arts Communication Society
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• v.15 no.2
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• pp.25-40
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• 1997

This research was carried out to investigated the effect of base paper and latex binder on printability and obtical properties of coated paper. Especially, it examined the effect of th pH of vase paper surface and functional groups of latices on the interactions between coating color components and on the structure of coated layer. It was found that the behavior of coating color containing amphoeric latex depends on the pH in the boundary region between coating color and base paper. Thus, the coating color formulated with amphoteric latex formed bulky coating layer by inducing stronger interaction between paper surface and coating components than the coating color with anionic latex. The coated paper with amphoteric latex showed better optical properties (i.e.gloss and optical) and printability (i.e. ink receptivity, wet ink receptivity, and ink set off) than the conventional anionic latex in the acidic and alkaline paper. However, dry pick strength of the coated paper was less decreased. This result indicated that amphoteric latex could also be applied practically to the alkaline paper.

• Journal of Korea Technical Association of The Pulp and Paper Industry
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• v.37 no.4 s.112
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• pp.52-59
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• 2005

Most of printing paper market today have been occupied by western paper and some machine-made Hanji used don't show the characteristic advantages for traditional hand-made Hanji. Although hand-made Hanji has an aesthetic and qualitative value, it has limited uses because of poor printability as printing paper. Unlike western paper, conventional Hanji cannot be used as Printing paper because it is impossible to make the clear formation of printed dot and to develop a high level of sizing and picking problem occurs during printing. Improvements of physical and optical properties such as roughness, smoothness, air permeability, contact angle, opacity, and paper gloss as well as sizing level were accomplished through internal and surface sizing and calendering, which made the paper better suited for printing and decreased problems during printing.

• Journal of Korea Technical Association of The Pulp and Paper Industry
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• v.44 no.3
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• pp.56-62
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• 2012

Recycled pulp therefore play a very important role in the paper industry today as a substitute for virgin pulp. In many countries of the world, the paper industry could not exist as it does without recycled pulp. Because, this is mainly due to economic reasons. Particularly in our country, the additional reason is the scarcity of native pulpwood resources. Therefore, the use of recycled pulp is very important. This study was aimed to apply recycled pulp to textbook paper. So we made a paper containing 30% recycled pulp and investigated about print quality, such as color reproduction, trapping, contrast, dot gain, gloss and print through. The results showed that is similar to existing textbook papers.

• Journal of Korea Technical Association of The Pulp and Paper Industry
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• v.29 no.4
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• pp.28-35
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• 1997

Sole-binder formulation has been recently introduced to solve the problems of coating process and printability caused by use of natural polymer However, the decrease of natural polymer application causes another problem in paper coating. Therefore, synthetic thickener is used to get similar effect to natural polymer usage. In this study. low shear viscosity, dewatering of coating colors were measured to evaluate the performance of the alkali sensitive water retention and rheology modifiers. The effects of alkali sensitive thickener on the physical properties of coated paper and printability were also investigated. The gloss and printability of coated paper containing the synthetic flow modifier were similar or superior to those of CMC containing coated paper. This modifier was also effective to improve the problems caused by the use of starch. The results indicated that the flow modifier synthesized with alkali sensitive thickener can reduce the problems of natural polymer and could be a good substitute f3r a natural polymer.

• Proceedings of the Korea Technical Association of the Pulp and Paper Industry Conference
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• 2006.06a
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• pp.91-98
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• 2006

The purpose of this study is to investigate the opacity and printing strength of MG paper overlaid plywood. The printing strength of ink on MG paper can be evaluated effectively by a formula $E^{*2}=[(L^{*})^{2}+(a^{*})^{2}+(b^{*})^{2}]^{1/2}$ that we proposed. Higher E value indicates good printing strength of ink-on-paper. We also assess the real color of translucent printed MG paper with a formula CIE ${\bigtriangleup}E^{*}$ (color difference between a pile of same paper to be opaque and fancy paper laminated board). In addition, the color difference on paper surface caused by the color of wood-based board (bottom) can be evaluated by a formula of Pc. No. Generally, an acceptable appearance quality of fancy boards is ${\bigtriangleup}E^{*}$ <2.0 and small Pc.No. value. The experimental results showed that Japan-made MG papers -J1, J2 and J3 have better printing strength and gloss than that of Taiwan-made paper (T1). The reason for this was that Taiwan-made paper has poor printing strength and low gloss, which might be correlated to the fiber compositions in paper. Higher printing strength can be seen for short fiber containing handsheets when comparing to that of handsheets. Nonetheless, low-freeness sheets gives better printing strength than that of high-freeness sheets. High-opacity MG paper gives good opacifying effect to the fancy paper laminated wood-based boards. Comparing the surface color of 2 kinds of fancy paper laminated boards, paperboard T1 laminated with high-opacity fancy paper showed slight color difference. The same results can be seen for $??g/m^{2}$ handsheets. Higher-opacity Acacia and Eucalyptus bleached sulfate pulps (short fiber) gives higher opacifying effect on the plywood when comparing to Northan pine and Radiata pine sulfate pulps(long fiber). The former ones also showed small color differences when comparing the color differences between the color of fancy paper and laminated paper board. Additionally, the color of bottom plywood can't be shown through for the high-opacify surface paper adhered to. Besides, the PC No of the base paper laminated board is small as well. Apparently, we can add colorants to the binders for the manufscture of various handsheets ($30g/m^{2}$) with various pulp mix ratios to increase the opacity of paperboards to certain extents. When we using yellow and brown binders in paper laminated board, the color difference between Acacia and Eucalyptus handsheets overlaid boards decreasing to 2.0 (acceptable ${\bigtriangleup}E^{*}$ <2.0, hard to discern), but not much improvement for Northern and Radiata pines. Definitely, show-through defects can be discernible for lower opacity papers. In general, admirable printing strength of fancy paper by which glued to plywood can be made with high-opacity paper and colored binders techniques.

• Journal of Korea Technical Association of The Pulp and Paper Industry
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• v.38 no.5 s.118
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• pp.47-53
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• 2006

To meet the ever increasing quality demand of coated papers and duplex boards, the local gloss variation and print unevenness must be avoid. To do this, surface roughening phenomenon which affects local gloss and print unevenness was investigated. In this study, the effect of roughness and densification of sheet obtained at various calendering conditions on surface roughening was examined. To evaluate the calendering effect properly we introduced a new value of roughening index by moisture for evaluation of surface roughening. Caliper and roughness of sheet decreased with increasing of calendering temperature and pressure, and the remarkable reduction of those properties occurred at the temperature around Tg. Roughening index increased when the amount of water increased and calendaring temperature and pressure increased. And as the sheet became denser by calendering, the roughening index increased to some extent. But roughening index by moisture is the lowest for sheet precalendered at higher temperature condition. When the surface of calendered sheet is rougher, there is more roughening of surface. The severe condition of calendering made the roughening index by moisture small.

• Journal of Korea Technical Association of The Pulp and Paper Industry
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• v.32 no.4
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• pp.81-86
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• 2000

Hanji is a traditional handmade paper, which has been famous for its excellent qualities in strength, whiteness, gloss, and smooth feel in painting and writing in ancient Far East for many years. Nowadays, however, its old fame has declined and it has been used only in limited extent such as in traditional Korean brush painting and writing. In this study, 9 kinds of commercial handmade papers made in Korea, China, and Japan were collected and their printing and writing properties were evaluated by image analysis. Chinese handmade paper showed the best result in absorption area of China ink, the roundness and feathering of China ink blots, followed by Hanji. Abrasion coefficient of the Chineses papers was higher than that of the others, which was regarded to contribute to the difference in touch feeling of the writing brush on the papers. It was shown that absorption rate and blot area of China ink were increased by Dochim. Hanji which has recently been made by so called \"traditional method\" showed no quality difference from the modified Hanji.ied Hanji.

• Journal of the Korean Graphic Arts Communication Society
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• v.23 no.2
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• pp.25-43
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• 2005

Generally, machine calendering are used change of paper surface properties. During machine calendering, dry paper passes between the rolls under pressure, thereby improving the surface smoothness and gloss. These improvements make the paper better suited for printing and decreasing problems during the printing, such as delayed dry and set-off. Then we investigated newspaper properties by the changing of machine calendering condition, and relationship printability. Properties of each samples were examined in accordance with KS and TAPPI standard test method i.e, basic weight, bulk density, thickness, porosity, opacity, brightness, smoothness and roughness. IGT printability tester was used to obtain ink requirement of newspaper, printed density and set-off. Results of in this study, we have proposed the optimizes range of newspaper calendering condition. Useful optimize calendering condition was pressure 55 kN/m, temperature $130^{\circ}C$.

• Journal of the Korean Graphic Arts Communication Society
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• v.24 no.1
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• pp.59-66
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• 2006

We studied on the effects of the enzyme treatment of pulp fiber on physical properties of coated paper were elucidated using four types of enzymes. The results of this study showed that the blank in which enzyme was not treated showed the highest $St{\ddot{o}}ckigt$ and Hurcules sizing degrees. And when the enzyme treated base paper was used for coating, the coated paper has average 5.7 % higher gloss and whiteness than when untreated base paper was used. Brightness showed 0.12 % higher results with the enzyme treated base papers than the blank while it is considered to show similar trends. Whiteness of coated paper was not influenced by the enzyme treatments but by the properties of coating color. Coated paper whose base paper was enzyme treated showed improved roughness while smoothness of those samples except the ${\beta}$-Glucosidase treated one was relatively low due to the high fines content. Also the coated paper whose base paper was not enzyme treated showed high porosity.