• Journal of Korea Technical Association of The Pulp and Paper Industry
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• v.33 no.3
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• pp.18-23
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• 2001

The effect of pulp consistency on the deinking properties in the ozone deinking of ONP was investigated in order to develop the environmentally friendly deinking method. The pulp consistency and ozone treatment time were varied for this purpose. Higher pulp consistency during ozone treatment gave better ink removal efficiency than the conventional deinking method. In was also found that the increase of pulp consistency can decrease the ozone treatment time which can meet the deinking quality. WRV of ozone deinked pulp obtained at 10% and 30% of pulp consistencies was lower than those of the conventional deinking method. However, the higher pulp consistency during ozone treatment improved WRV. Highest brightness was obtained at the ozone treatment condition of 30% pulp consistency and 10 minutes. The lower brightness at the other ozone treatment condition should be originated from the excessive decrease of ink particle size and then decrease of true ink removal efficiency. Scott bond was increased with the increase of pulp consistency and treatment time. However, the improvement of breaking length with ozone treatment was no significant.

• Journal of Korea Technical Association of The Pulp and Paper Industry
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• v.33 no.3
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• pp.24-28
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• 2001

The utilization of wastepaper as a papermaking raw material is everlastingly required for the environmental protection of earth. However the recycling of wastepaper for this purpose cause another problem such as the increasing of the load of wastewater treatment, lower strength properties of paper, and poor printability, etc. The interest in the development of the environmentally friendly deinking technology is increased continuously. Thus, our research team have tried to apply the ozone to the deinking of white ledger and ONP, and obtained the positive results which can be considered as an alternative method for the conventional deinking method. The purpose of this study is to investigate the mechanism of ozone deinking. Styrene acrylate and polystyrene were treated with ozone and measured the change of molecular weight with the GPC. The molecular weight distribution obtained with GPC showed only slight increase by the ozone treatment, and gel formation by the polymerization was observed. Therefore the removal of ink particles with ozone treatment seems to be facilitated by the increase of the brittleness and decrease of adhesive property.

• Journal of Korea Technical Association of The Pulp and Paper Industry
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• v.32 no.2
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• pp.40-44
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• 2000

A microscopic study was carried out to get the fundamental informations for the ozone deinking technology. The differential interference microscopic observation showed that ozone treatment was helpful to detach the toner ink from the surface of pulp fiber. The modifications of fiber surfaces by ozone treatment were observed with scanning electron microscope. Modification of fiber surfaces was not severe at the early stage of ozone treatment, but it increased with ozone treatment time and pulp consistency, Therefore, it would be possible to improve the properties of deinked pulp by controlling the condtion of ozone treatment.

• Journal of Korea Technical Association of The Pulp and Paper Industry
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• v.32 no.1
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• pp.41-47
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• 2000

The objective of this study is to assess the possibility of ozone as an environmentally friendly new deinking alternative for conventional deinking method. It is well known that the white ledger is very difficult to deink because the toner ink has the peculiar shape and size. Ozonization could remove the ink particles above 300 microns and thus improved the ink removal efficiency. Ozonization also improved the WRV of recycled fiber and apparent density, scott bond strength , breaking length, double fold and tear index. Thus, we believe that ozonization could be used as a deinking means of white ledger instead of the convention미 deinking method.