• Journal of Korea Technical Association of The Pulp and Paper Industry
• /
• v.43 no.3
• /
• pp.30-34
• /
• 2011

This study was carried out in order to evaluate the effect of coated weight and calender pressure on conductivity of printed RFID tags. The printed RFID tags have been manufactured with gravure printing and it has been well known that the efficiency of printed RFID tags is influenced by surface properties of substrate. In this study, coated paper was prepared with four different coated weight and three different calender pressure. After printing conductivity ink on coated paper, surface resistance was measured to evaluate the efficiency of the printed RFID tag. It was found that, with increasing of coated weight and calender pressure, the paper gloss, smoothness, brightness and gravure printability were improved while the surface resistance of the printed RFID tag was decreased.

• Journal of Korea Technical Association of The Pulp and Paper Industry
• /
• v.45 no.6
• /
• pp.36-43
• /
• 2013

Effects of blending of PCC manufactured with emission gas occurred at mill on the characteristics of coating color, optical and printing properties of coated paper were investigated in order to evaluate the possibility of its use as a raw material for producing environmentally friendly coated paper. Low shear viscosity and water retention value of ground PCC 1(d50 = $6.303{\mu}m$) were higher than those of ground PCC 2(d50 = $3.149{\mu}m$). Ink set properties of ground PCC 1 and ground PCC 2 were inferior to that of PCC 3. Thus, the reducing of particle size was required in order to overcome the inferior ink set properties. Ground PCC 1 had a similar properties to clay, and it showed the possibility that ground PCC 1 could be used to produce matte grade coated papers. However, it was required to improve the stability(particle shape, particle size, and compatibility with chemicals used in coating color formulation) in the case of blending with GCC in order to keep the qualities of coated paper.

• Journal of Korea Technical Association of The Pulp and Paper Industry
• /
• v.47 no.5
• /
• pp.134-140
• /
• 2015

This study was carried out to evaluate whether EVAc, acryl latex and biobinder could substitute the part of SB latex for pre-coating color formula or not. Different coating colors prepared through the substitution of 30% SB latex with EVAc, acryl latex, and biobinder were applied for pre-coating layer. 100% SB latex is used as a binder for top coating color. The optical properties, gloss, roughness, stiffness, dry- and wet-pick strength were measured. There were no significant differences in the brightness, whiteness, opacity, roughness, ink set-off and gloss of paper coated with 5 different coating colors. However the stiffness, dry- and wet-pick strength were somewhat lower than those of conventional coating color which 100% SB latex was used as a binder. Although the part of SB latex could be substituted with EVAc, acryl latex and biobinder without sacrificing the qualities of coated paper. Further researches on the improvement of stiffness, dry- and wet-pick strength, and the optimization of rheology of coating color in order to improve the qualities of coated paper are strongly recommended.

• Journal of Korea Technical Association of The Pulp and Paper Industry
• /
• v.32 no.4
• /
• pp.49-57
• /
• 2000

This study was carried out to investigate the effect of the type of base papers containing rice straw-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 rice straw-BKP was observed much shorter than those of the wood pulps(Sw-BKP, Hw-BKP). This has effect on physical properties. Therefore, the results of measured physical properties were much lower than those of wood pulps. Also, physical properties tended to increase slightly with the increase of the mixing ratio of Sw-BKP. Opacity of the base paper containing rice straw-BKP, was higher than that of the wood pulps. As the mixing ratio of Sw-BKP increases the opacity tended to decrease. On the other hand, smoothness and roughness to rice straw-BKP were similar with Sw-BKP and its air permeability was lower than those of wood pulps. The optical properties of coated papers containing rice straw-BKP tended to be similar to those of other base papers. The ink receptivity of coated papers containg rice straw-BKP was higher than those of wood pulps and printing gloss was similar to wood pulps. The mixing ratio of Sw-BKP, the ink receptivity and printing gloss of rice straw-BKP were showed no difference irrespective the mixing ratio of Sw-BKP. Meannwhile, amphoteric latex improved the optical properties and printability of coated papers.

• Journal of Korea Technical Association of The Pulp and Paper Industry
• /
• v.42 no.1
• /
• pp.26-34
• /
• 2010

Effects of drying condition (IR radiation) on the optical properties and the printability of coated paper were elucidated at various latex sizes and low and high coating color concentrations. It was found that the smaller latex provided better rheology and higher dry and wet pick strength than the larger one. The high solids coating resulted in higher paper gloss and smaller roughness than the low solids coating, even though the clay addition was reduced by 20 parts in the high solids coating. Increasing IR radiation prohibited binder migration into the base paper. Thus it improved binder distribution and decreased pores in the coated layer, resulting in the increased dry and wet pick strength and the improved printing gloss. On the other hand, the color trapping and ink set-off was impaired with increasing IR radiation. Print mottle index passed through a maximum with increasing IR radiation.

• Journal of Korea Technical Association of The Pulp and Paper Industry
• /
• v.47 no.5
• /
• pp.127-133
• /
• 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.

• Journal of the Korean Graphic Arts Communication Society
• /
• v.23 no.2
• /
• pp.25-43
• /
• 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 $130^{\circ}C$.

• Proceedings of the Korea Technical Association of the Pulp and Paper Industry Conference
• /
• 2006.06a
• /
• pp.91-98
• /
• 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
• /
• v.44 no.5
• /
• pp.32-38
• /
• 2012

This study was carried out to elucidate the potential in substitution of SB latex with eco-friendly starch based bio-binder as a coating binder. The part of SB latex in coating color of pre- and top layer was substituted with starch based bio-binder in order to evaluate the characteristics of coating color and coated paper, and printability. The viscosity and water retention of coating color were increased by substitution of SB latex with starch based bio-binder. Roughness of coated paper was increased by substitution with starch based bio-binder, although there was not significant changes in roughness when SB latex is used as a binder in pre-coating color. Brightness and whiteness of coated paper were not affected, but opacity and print mottle were improved by substitution with starch based bio-binder. The interesting result observed was that dry-pick did not affected significantly, and ink set-off was improved by starch based bio-binder. It is expected that starch based bio-binder can be commercialized if the systematic further research works are carried out.

• Journal of Korea Technical Association of The Pulp and Paper Industry
• /
• v.33 no.4
• /
• pp.28-34
• /
• 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.