Application of in-situ CaCO_3 forming process on recycled fibers for optical property improvement

Abstract

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 2 O 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.

Application of In-situ CaCO3 Formation Method for Better Utilization of Recycled Fibers (2)

“…[1][2][3][4][5][6] Park 등1) 은 in-situ 탄산칼슘형성 방 식을 사용하여 ONP의 수율의 감소가 없이 10-15%의 백색도 증가를 기록하였다. 1) 이러한 경우 지료의 백색도 향상은 물론이고, 유색 협잡 물들을 새로 생성되는 탄산칼슘이 감쌈으로서 ERIC (effective residual ink concentration) 값이 현저히 낮아 지는 결과를 초래하였으며, 탄산칼슘과 지료의 결합이 우수해져 초지 시 보류향상제의 첨가가 없이도 상당한 수준의 보류가 이루어짐을 보고한 바가 있다.…”

The Improvement of Recycled Newsprint Properties by In-situ CaCO3 Loading

“…They used more white ledger furnish for the printing grade paper without losing optical and strength properties by the application of the in-situ CaCO3 formation method and by controlling the refining process. Park et al (2012) and Lee et al (2013) also showed that the increase in the optical properties with a bleaching process was inferior to that of the in-situ CaCO3 formation method for ONP furnish. Actually, bleaching ONP caused a significant yield loss in the furnish.…”

“…The in-situ CaCO3 loading method on ONP improved the brightness, the effective residual ink concentration (ERIC) value, and ash retention greatly (Park et al 2012;Lee et al 2013). In this study, we investigated the mechanism responsible for the ERIC value improvement, macro sticky area changes, retention behaviors, as well as mechanical and morphological changes caused by the in-situ CaCO3 loading method.…”

“…Actually, bleaching ONP caused a significant yield loss in the furnish. Park et al (2012) and Lee et al (2013) separated fibers from fines by fractionation of ONP furnish and examined their morphological changes by scanning electron microscopy (SEM) and optical microscopy using a FlowCAM ® dynamic imaging particle analyzer, a new type of colloidal size analyzer capable of showing optical images of colloidal materials. From the optical images, the formation of CaCO3 on the ONP was apparent.…”