• 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.38-46
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• 2006

Many researches for extensive uses of Hanji have been performed. With the advent of an information-oriented age, the development of Hanji which is printable has been considered as a new field of study. Since Hanji has many drawbacks in comparison with common printing papers, that is, rougher surface, huger absorption of ink and lower physical properties and printabilities. Improving the properties and printabilities of Hanji is therefore the most important work to deal with. This study was conducted to find out useful mixed agents for surface sizing suitable for printable Hanji. Four surface sizing agents (CMC, corn starch, PYA, AKD) were applied for mixture in this study. The physical properties of surface sized Hanji were measured. Results obtained were as follows. Based on designated agents according to concentration, each of the mixed agents was prepared. The kinds of mixture were corn starch (3%) and PVA (5%), corn starch (3%) and AKD (0.1%), corn starch (3%) and CMC (1%), AKD (0.1%) and CMC (1%), AKD (0.1%) and PVA (5%), CMC (1%) and PVA (5%). Each mixed surface sizing agents was included with these ratios (100:0, 90:10, 70:30, 50:50, 30:70, 10:90, 0:100) respectively. All the mixed agents improved the physical properties and printabilities of Hanji. Among them, mixed agent of CMC (1%) and corn starch (3%) with 90:10 ratio is superior to the others for not only smoothness but also ink printability. In view of the result achieved, it is regarded that it can be fit for using Hanji as a printing paper and turned out to be a good contribution to Hanji industry.

• Fibers and Polymers
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• v.6 no.2
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• pp.174-179
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• 2005

The present paper studies the effect of chitosan, cationic starch and polyvinyl alcohol (PVA) as sizing agents to enhance surface properties of kenaf paper. The polymers were incorporated into the sheets by spray application. The results clearly showed that the addition of chitosan to a sheet formed from beaten fibers had excellent improvement in surface properties, compared to the effect of other additives. Sizing quality of cationic starch fairly matched with the sizing quality of chitosan, however, it was able to reduce the water absorption potential of paper more than chitosan at a same concentration. In most other properties, particularly the most important property for printing papers, surface smoothness, chitosan-sized papers are superior to the paper sized with cationic starch or PVA.

• Journal of Korea Technical Association of The Pulp and Paper Industry
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• v.37 no.1 s.109
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• pp.73-81
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• 2005

Stockigt sizing test, which is readily affected by individual tester's bias as well as testing conditions in recognizing red coloration, had to be modified to improve its reliability and reproducibility. The novel testing system with the automatic recognizing program of red coloration was developed with the auxiliary equipments including an automatic liquid dispenser and a specimen shifter. The analysis program used a hue value of a droplet image in recognizing a point of time on red coloration instead of RGB values that are not similar to human perception of color. Hue was more sensitive in recognizing the red coloration of a droplet than the other two factors, Saturation and Value. During the test, the program records the time consumed up to a specific hue value of a droplet on a specimen. Differently from the conventional test, the automatic test could obtain a reliable and reproducible sizing degree with a minor error. Furthermore, the Stockigt sizing degree measured by the automatic system showed great correlations with contact angle and Hercules sizing degree. It means that such great correlations will contribute to the development of an integrated measuring system capable of predicting contact angle, surface tension, surface energy and Hercules sizing degree of paper and paperboards through the Stbckigt sizing test. It was meaningful to note that the automatic system for Stbckigt sizing test might be able to used to predict contact angle, Hercules and Cobb sizing degree, based upon the high correlation coefficients.

• Journal of Korea Technical Association of The Pulp and Paper Industry
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• v.37 no.5 s.113
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• pp.70-77
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• 2005

The development of printable Hanji is regarded as an important work to create a new demand of Hanji in information-oriented era. Hanji has rougher surface, huger absorption of ink and lower optical properties and printabilities than common printing papers. Improving those shortcomings of Hanji is required to be printable Hanji. Sizing and calendering have known as a way to make properties of paper good. Accordingly, this research was performed to find out useful sizing agents for reforming its drawbacks. Four sizing agents (CMC, com starch, PVA, AKD) were used in this research. The optical properties and the printabilities of sized Hanji were tested. The obtained results were as follows. Based on concentration, each sizing agent was prepared. These were CMC(0.5, 1, $1.5\%$), corn starch(1, 2, $3\%$), PVA(1, 5, $10\%$), AKD(0.5, 0.1, $0.15\%$) respectively. After sizing, we performed calendering treatment with pressure of 0.5, $1\;kgf/cm^2$. All the sizing agents and calendering treatment improved the properties of Hanji to some extent. Particularly, com starch was good for gloss. In case of printability, $1\%$ AKD with $1\;kgf/cm^2$ was recommendable for typography ink density, $3\%$ com starch with $0.5\;kgf/cm^2$, inkjet ink density, $2\%$ com starch with $0.5\;kgf/cm^2$, inkjet ink girth. PVA and AKD without calendering were counter-effective agents for inkjet ink density. Printable Hanji is required to have not only better surface strength enough to appear non-picking, higher ink density and lower show-through than base paper but also the lowest ink girth in comparison with base paper. When referring to them, efficient sizing agents were regarded as $0.1\%$ AKD with $1\;kgf/cm^2$, calender pressure, for typography printing and $2\%$ com starch with $0.5\;kgf/cm^2$, calender pressure, for inkjet printing.

• Journal of Korea Technical Association of The Pulp and Paper Industry
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• v.45 no.4
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• pp.9-15
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• 2013

An oxidized starch ester was prepared and used for surface sizing. Esterification of starch decreased both Brookfield viscosity and Brabender viscosity substantially even though the solids level was increased by 2% from 14% to 16%. Surface sizing with the esterified starch gave better performance in tensile strength, stiffness and compressive strength than surface sizing with oxidized starch in the laboratory. Advantages in strength improvement, however, were not obtained when it was applied in commercial papermaking process. This was attributed to the fact that the influence of starch types has been nullified by high pressure penetration that occurs in the commercial papermaking process. Drying energy consumption, however, decreased by 3.3% by substituting the low solids oxidized starch with a high solids starch ester.

• Journal of Korea Technical Association of The Pulp and Paper Industry
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• v.46 no.6
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• pp.50-55
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• 2014

An oxidized starch was modified for surface sizing via etherification and esterification. Propylene oxide (PO), sodium monochloroacetate (SMCA), and acrylonitrile (AN) were used as etherification, and vinyl acetate monomer (VAM), maleic anhydride (MA), fumaric acid (FA), and itaconic acid (ITA) were used for esterification. Esterification and etherification of starch decreased both Brookfield viscosity and Brabender viscosity substantially even though the solids level was increased by 2% from 14 to 16%. Surface sizing performance of starches in tensile strength, stiffness and compressive strength was improved by esterification and etherification of the oxidized starch. Especially, SMCA etherification was found to be the most effective modification method.

• Carbon letters
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• v.5 no.1
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• pp.1-5
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• 2004

The effects of fiber surface-treatment and sizing on the dynamic mechanical properties of unidirectional and 2-directional carbon fiber/nylon 6 composites by means of dynamic mechanical analysis have been investigated in the present study. The interlaminar shear strengths of 2-directional carbon/nylon 6 composites sized with various thermosetting and thermoplastic resins are also measured using a short-beam shear test method. The result suggests that different surface-treatment levels onto carbon fibers may influence the storage modulus and tan ${\delta}$ behavior of carbon/nylon 6 composites, reflecting somewhat change of the stiffness and the interfacial adhesion of the composites. Dynamic mechanical analysis and short-beam shear test results indicate that appropriate use of a sizing material upon carbon fiber composite processing may contribute to enhancing the interfacial and/or interlaminar properties of woven carbon fabric/nylon 6 composites, depending on their resin characteristics and processing temperature.

• Journal of Korea Technical Association of The Pulp and Paper Industry
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• v.41 no.5
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• pp.1-7
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• 2009

Oxidized acetate starch was synthesized from corn oxidized starch and vinyl acetate. The sizing concentration and degree of substitution of modified starch on surface strength, smoothness and water resistance of the paper have been studied. The results showed that the surface strength, smoothness and other properties of paper sized by oxidized acetate starch is better than that of oxidized starch. When the degree of substitution of modified starch is from 0.04 to 0.14, the properties of paper sized by oxidized acetate starch have been improved more effectively.

• Composites Research
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• v.31 no.6
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• pp.379-384
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• 2018

This paper aims to study flow characteristics of epoxy resin w.r.t. the sizing agents treated on the carbon fibers which have the same surface morphologies before sizing treatment. Dynamic contact angle (DCA) was measured to evaluate wettability of a single carbon fiber. Wicking test and Vacuum Assisted Resin Transfer Molding (VARTM) were performed to find relation between DCA measurement results and impregnation characteristics. In addition, surface properties of the carbon fibers such as surface free energy and chemical compositions were measured and interfacial shear strength (IFSS) between the carbon fiber and the resin were experimentally characterized by using micro-droplet tests. According to these experimental results, the sizing agent for carbon fibers should have appropriate level of surface free energy and good chemical compatibility with the resin to reconcile resin flow characteristics and interfacial strength.

• Journal of Korea Technical Association of The Pulp and Paper Industry
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• v.33 no.2
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• pp.17-23
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• 2001

AKD sizing behavior of handsheets, which were prepared from the different pulps with various AKD fixing agents, was studied in this investigation. AKD sizing performance could be improved by removal of fines in the stock, minimizing damage of fiber, using a suitable fixing agent and heat treatment. Fillers with low surface energy, like calcium carbonate and talc, showed quite positive effect in AKD sizing. When PAM was added to the DIP stock as fixing agent, it showed lower sizing degree than polyamine did. But in case of NBKP system, PAM was more effective than polymine.