PAPER making! FROM THE PUBLISHERS OF PAPER TECHNOLOGY INTERNATIONAL O U S SO Volume 6, Number 1, 2020
Effect of Recycling Number on the Fluorescence Reduction of Fluorescent Whitening Agents in White Wastepapers Ji Young Lee 2 , Chul Hwan Kim 2 , Hae Min Jo 1 , Kyung Min Kim 1 and Su Ho Kim 2 . White wastepaper is a very important resource in the Korean paper industry. However, its use is limited because it contains fluorescent whitening agents (FWAs). To improve the use of recycled white wastepaper, FWAs should be removed. The first step in eliminating FWAs from wastepaper is to analyze the behavior of FWAs from wastepaper during the recycling process. In this study, the effect of recycling on FWA detachment from white wastepaper and the distribution change of FWAs in the sheet was investigated. Disulfo-,tetrasulfo- and hexasulfo-FWAs commonly found in paper were prepared and recycled many times through a laboratory process. After each round of recycling, the optical properties and fluorescence index of the sheet were measured, and the fluorescence reduction was calculated as an indicator, which represents the FWA detachment from wastepaper, using fluorescence indices before and after recycling. The FWA distribution in the paper cross section was observed using a CLSM. Disulfo-FWA exhibited a lower fluorescence reduction and even distribution in the paper cross section; however, surface-treating FWAs, including tetrasulfo-FWA, and hexasulfo-FWA, extensively desorbed from the paper during the recycling process. The surface-treating FWAs showed similar distributions in paper cross section after the recycling because of their readsorption on the fibers. Therefore, surface-treating FWAs can be detached easily compared with internal FWAs, and some detached FWAs can re-adsorb on cellulosic fibers during the recycling process. Contact information: 1 Department of Forest Products, Gyeongsang National University, Jinju-daero, 501, Jinju, 52828, Republic of Korea. 2 Department of Environmental Materials Science/IALS, Gyeongsang National University, Jinju-daero, 501, Jinju, 52828, Republic of Korea. Journal of Korea TAPPI, Vol. 51. No. 2, 2019, 49-57p, ISSN (Print): 0253-3200 http://dx.doi.org/10.7584/JKTAPPI.2019.04.51.2.49
The Paper Industry Technical Association (PITA) is an independent organisation which operates for the general benefit of its members – both individual and corporate – dedicated to promoting and improving the technical and scientific knowledge of those working in the UK pulp and paper industry. Formed in 1960, it serves the Industry, both manufacturers and suppliers, by providing a forum for members to meet and network; it organises visits, conferences and training seminars that cover all aspects of papermaking science. It also publishes the prestigious journal Paper Technology International and the PITA Annual Review , both sent free to members, and a range of other technical publications which include conference proceedings and the acclaimed Essential Guide to Aqueous Coating .
Article 5 – FWAs and Recycling
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