Proceedings of the Korea Technical Association of the Pulp and Paper Industry Conference (한국펄프종이공학회:학술대회논문집)

Korea Technical Association of the Pulp and Paper Industry (한국펄프종이공학회)
권호 표지

A SPECTROSCOPIC STUDY OF THE OPTICAL PROPERTIES OF VARIOUS PAPERS MADE FROM RECLAIMED FIBRES

  • Ingegerd Forsskahl (The Finnish Pulp and Paper Research Institute (KCL), Paper Science Centre, Finland) ;
  • Carola Olkkonen (Department of Chemistry, University of Helsinki, Finland) ;
  • Henrik Tylli (Department of Chemistry, University of Helsinki, Finland)
  • Published : 1999.04.01

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Abstract

Different papers such as toilet and towel tissue, newsprint and copy paper made from reclaimed fibres were characterized using UV-VIS reflectance and fluorescence spectroscopy. The emission properties of the extracts of the papers were also evaluated. Photochemical irradiation at ambient temperatures, and thermal aging of the copy papers at 105$^{\circ}C$ and 150$^{\circ}C$ were performed. Post-colour numbers (PC) were calculated from the reflectance values measured from the corresponding UV-VIS reflectance spectra. Light absorption coefficient spectra were calculated before and after irradiation, and the changes in absorption coefficient were related to the content of chromophores in the papers. Photochemical and thermal discolouration of the copy papers, similar to that of virgin fibres, was readily observed. The influence of changes in the concentrations of fluorescent brightening agents and dyes on the spectral properties was also assessed. Photostabilization studies of the copy papers were performed with the use of polymer additives polyethylene glycol (PEG) and polytetrahydrofuran (PTHF).

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