• Title/Summary/Keyword: in-situ $CaCO_3$ forming

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Application of In-situ CaCO3 Formation Method for Better Utilization of Recycled Fibers (2) - Comparison with CaCO3 Addition Method and Effects of Temperature - (고지의 효과적인 활용을 위한 in-situ 탄산칼슘 부착방식의 연구(2) - 탄산칼슘 첨가방식과 비교 및 반응온도에 따른 변화 -)

  • Lee, Min Woo;Lee, Young Ho;Jung, Jae Kwon;Seo, Yung Bum
    • Journal of Korea Technical Association of The Pulp and Paper Industry
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    • v.46 no.5
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    • pp.27-34
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    • 2014
  • In-situ $CaCO_3$ formation onto recycled wood pulp was studied to improve optical properties and ash attachment to the fiber furnish in papermaking. We controlled initial reaction temperature of in-situ $CaCO_3$ formation method from $30^{\circ}C$ to $50^{\circ}C$. It was found that the attachment of newly formed $CaCO_3$ to recycled fibers, old newspaper (ONP) in this case, was stronger than that of ground calcium carbonate (GCC, mean dia. $2.4{\mu}m$) addition case, but was not much different among those formed at different temperature. Morphologies of newly formed $CaCO_3$ were changed according to the reaction temperature. More aragonite shape was seen at higher temperature. In-situ $CaCO_3$ formation increased brightness and lowered ERIC value of ONP sheet greatly at the same level of ash contents when compared to GCC addition method, but gave equivalent ERIC and brightness when compared to those of the precipitated calcium carbonate (PCC) addition method. However, tensile strength of the handsheets of the in-situ $CaCO_3$ formation method were much greater than those of the PCC addition method.

Application of in-situ CaCO3 forming process on recycled fibers for optical property improvement (고지의 광학적특성 개선을 위한 in-situ 탄산칼슘처리기술의 적용)

  • Park, Dong-Hui;Lee, Min-Woo;Lee, Jong-Kyu;Ahn, Ji-Whan;Seo, Yung-Bum
    • Journal of Korea Technical Association of The Pulp and Paper Industry
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    • v.44 no.4
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    • pp.8-15
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    • 2012
  • Optical property improvements for ONP (old newspaper) and OMG (old magazine) were attempted by application of in-situ $CaCO_3$ formation process on recycled fiber surfaces. Washing treatment of ONP and OMG resulted in 35~40% yield loss for around 6% brightness improvement. Washing plus bleaching process with $H_2O_2$ and FAS (formamidine sulfinic acid) improved brightness and ERIC values a little more with the same amount of yield loss as washing treatment. In-situ $CaCO_3$ formation method improved those optical properties much better than the washing plus bleaching method without loss of yield, and better than the case of adding high brightness PCC up to the same ash level. It can be said that the in-situ $CaCO_3$ formation method may be used as an effective alternative for upgrading optical properties of recycled fibers.

Morphological and Physical Properties of ONP Treated by CaCO3 In-situ Precipitation Method (탄산칼슘 in-situ precipitation 처리된 신문고지의 형태와 물성변화)

  • Lee, Young Ho;Jung, Jae Kwon;Lee, Ki Seung;Seo, Yung Bum
    • Journal of Korea Technical Association of The Pulp and Paper Industry
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    • v.45 no.6
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    • pp.44-54
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    • 2013
  • Replacing OMG (old magazine) to ONP (old newspaper) by raising optical property through $CaCO_3$ in-situ precipitation method in white duplex board presents cost reduction and possible drying energy saving. The strength property impairment by the presence of $CaCO_3$ could be supplemented by the fiber furnish treatment or strength polymer addition. In $CaCO_3$ in-situ precipitation of ONP, it was found from morphological study using FlowCAM, an image analyzer, that most of calcium carbonate were formed on the fines, and made the size of the fines larger. For the case of forming calcium carbonate only on the fractionated fines, the size of the fines were the biggest, and there were more clean surface areas available for bonding for the fractionated long fibers when fractionated fibers and fines were regrouped to make paper.