• Journal of Korea Technical Association of The Pulp and Paper Industry
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• v.40 no.3
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• pp.1-8
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• 2008

The efficiency of retention systems including compozil-G, hydrocol, compozil-S, and micropolymer under highly closed papermaking system was evaluated using contaminated white waters prepared in the laboratory. Compozil-G and compozil-S performed better in retention than hydrocol and micropolymer systems. This suggested that stronger hydrogen bonding between fiber and guar gum or starch was formed to give stronger flocculation and better retention. Especially compozil-G outperformed compozil-S in retention, and this indicated the presence of stronger interaction between guar and cellulose fibers probably due to their similarity in chemical structure. Two compozil retention systems decreased the cationic demand and COD more effectively than hydrocol and microparticle systems. In particular, compozil-G that uses guar gum was highly effective in decreasing anionic trashes at low dosage.

• Journal of Korea Technical Association of The Pulp and Paper Industry
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• v.30 no.2
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• pp.30-39
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• 1998

Effect of cationic starches and anionic colloidal silica on retention and drainage characteristics of Compozil system was investigated. Depending upon the degree of substitution and molecular weight of cationic starches and morphological characteristics of anionic colloidal silica, retention and drainage properties of Compozil system were significantly influenced. When cationic starch addition level increased above a certain limit retention and stock freeness were decreased. To elucidate this an electrostatic coagulation mechanism occurring between unadsorbed starch molecules and anionic colloidal silica was proposed. Unstructured colloidal silica showed greater improvement in retention than structured colloidal silica. Cationic corn starches with different degree of substitution and molecular weights were prepared and their effect as a constituent of Compozil system was also evaluated. By controlling the molecular weight and degree of substitution of cationic corn starch it was possible to achieve significant improvement in fines retention. Cationic corn starch with higher degree of substitution maintained its retention efficiency even when the stock conductivity was increased. Turbidity measurement technique was found to be a simple and useful method to measure the retention characteristics.

• Journal of Korea Technical Association of The Pulp and Paper Industry
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• v.31 no.5
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• pp.24-30
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• 1999

Crosslinked corn starches were prepared to increase their molecular weights and their performance as a component of Compozil system was evaluated and compared with that of potato starches. It was shown that greater improvements in retention and strength properties could be achieved when crosslinded cationic corn starches rather than conventional cationic potato starches were used especially at high conductivity because of their molecular rigidity.

• Journal of Korea Technical Association of The Pulp and Paper Industry
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• v.35 no.5
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• pp.1-9
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• 2003

Effectiveness of the microparticle retention systems in improving drainage, retention, formation has been recognized for many years. In this study the effectiveness of crosslinked cationic corn starches and silica-based microgels as components of Compozil system has been evaluated. It was shown that improvements in retention and strength could be achieved by employing crosslinked cationic corn starches especially at high conductivity. Silica-based microgels with better performance in retention and drainage than a commercial colloidal silica sol have been made through a reaction of sulfuric acid and sodium silicate solutions.

• Journal of Korea Technical Association of The Pulp and Paper Industry
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• v.32 no.1
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• pp.26-32
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• 2000

The impact of major surface chemical properties of silica sols on the retention and drainage performance of the silica based micrparticle system, Compozil was investigated using four different silica sols. And the effect of silica properties on the interactions with cationic starch and cationic plyacrylamide has also been identified. The surface charge density and the stability over pH of silica sols were increased by introducing aluminosilicate anions at surface. It was found that the charge density of silica sols determined the addition level necessary to attain the maximum retention and drainage. When silica sols were combined with cationic starch, the change density of the product was the critical properties and the degree of microagregation was of minor importance. In the cationic polyacrylamide system the degree of colloid structure appeared to be a more critcial property than the charge density of silica sols.

• Proceedings of the Korea Technical Association of the Pulp and Paper Industry Conference
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• 1999.11b
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• pp.43-49
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• 1999

Effectiveness of the microparticle retention systems in improving dramage, retention, formation has been recognized for many years (1, 2, 3, 4, 5). In this study the effectiveness of crosslinked cationic corn starches and silica-based microgels as components of Compozil system has been evaluated. It was shown that improvements in retention and strength could be achieved by employing crosslinked cationic corn starches especially at high conductivity. Silica-based microgels with better performance in retention and dramage than a commercial colloidal silica sol have been made through a reaction of sulfuric acid and sodium silicate solutions.

• Journal of Korea Technical Association of The Pulp and Paper Industry
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• v.32 no.1
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• pp.33-40
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• 2000

The effectiveness of silica-based microgels prepared through the reaction of sulfuric acid and sodium silicate as a component of Compozil system has been evaluated . Silica based microgels with better performance in retention and drainage than a commercial colloidal silica sol have been successfully prepared. Silica gels with the highest charge density were obtained when product pH was controlled to 9. And highly charged silica-based microgels showed greater retention and freeness performance than a commerical product. In particular the difference in retention, turbidity , and freeness between these microgels and a commercial product was eminent at low addition rate. The effects of reaction conditions including reaction temperature, process water quality and feeing rate on product efficiency in improving retention and drainage were also investigated and discussed.

• Applied Chemistry for Engineering
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• v.7 no.2
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• pp.315-320
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• 1996

In this paper, we investigated the retention amounts(ash contents) according to the addition amounts of retention aid and calcium carbonate and compared the mechanical and optical properties of sheets under the same ash content. As the addition amounts of retention aid increase, the retention of calcium carbonate, that is, ash contents of sheets increase in all retention system. In this case, the sheets included ash content as already expected is produced by adjusting the addition amounts of retention aid and calcium carbonate. Tensile index, burst index, tear index, internal bonding strength of sheets straightly decrease as the ash content of sheets increases. Especially, in the same ash content, all sorts of strength are high in compozil system, low in dual polymer system. Opacity increases along with according to the increase of ash content, and is high in hydrocol system, the worst in dual polymer system. In equal opacity, the strength of paper decreases compozil, hydrocol, and dual polymer system in order. But to judge she superiority or inferiority of retention aids, it should consider the various factors such as the optimum production and process conditions besides the retention amounts of filler and the sheet strength.

• Journal of Korea Technical Association of The Pulp and Paper Industry
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• v.29 no.4
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• pp.45-52
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• 1997

This study was carried out to investigate the adsorption characteristics of cationic starches onto BKP, BCTMP and talc. Concentration of the unadsorbed cationic starch contained in the supernatant of the pulp or talc slurries was determined using a spectoscopy method and the adsorption isotherm of cationc starch was constructed. When the equilibrium concentration of the cationic starch was low, almost complete adsorption of the starch onto BKP and BCTMP was observed. This indicates that electrostatic attraction is the main driving force for the adsorption of cationc starches onto pulps. BCTMP adsorbed greater amount of cationic starches than BKP since it contained more anionc functional groups on its surface. The adsorption amount of the cationic starch increased as the cationicity of the starches decreased. Surface charge density of the pulp and starch adsorption increased as the pH of the pulp slurry increased. Adsorption amount of the cationic starch onto talc was lower than that onto the pulp due to its low charge density and hydrophobic surface property.