Confocal Raman microscopy in chemical and physical characterization of coated and printed papers
No Thumbnail Available
Journal Title
Journal ISSN
Volume Title
Doctoral thesis (article-based)
Checking the digitized thesis and permission for publishing
Instructions for the author
Instructions for the author
Unless otherwise stated, all rights belong to the author. You may download, display and print this publication for Your own personal use. Commercial use is prohibited.
Author
Date
2004-10-22
Major/Subject
Mcode
Degree programme
Language
en
Pages
70, [25]
Series
Report / Helsinki University of Technology, Laboratory of Forest Products. Series A, 18
Abstract
In offset printing on coated papers an uneven print, mottling, is a serious problem. Uneven styrene-butadiene (SB) latex distribution may be the reason for the mottled print. In this work, confocal Raman microscopy methods were developed for chemical and physical characterization of printed and coated papers. The main emphasis was laid on analysis of the SB-latex distribution in x-y-z direction. A depth profiling method was developed. An immersion method was found to be essential in the depth profiling of light scattering coated papers. Model samples were employed to obtain a better understanding of the depth profiling method. The method was applied in the analysis of SB-latex migration and measurement of the thickness of paper coating layers and ink films. Lateral mapping of paper coatings was developed for bulk and surface analysis. In mapping of coating bulk, the whole coating layer was measured and the analysis could be done through print. Lateral mapping of the bulk layer provided information on SB-latex distribution, and variations in coat weight and ink density could be mapped simultaneously. Bulk mapping was combined with light microscopy images acquired from the same area. A higher magnification objective gave the means to measure the outermost 1-2 µm of the coating layer. Analysis of the coating surface is important because of the ink–coating interaction taking place on the coating surface. In the surface analysis, SB-latex content and its variation in different scales were of interest. The total areas analysed contained many areas of 1 mm × 1 mm.Description
Keywords
Raman, depth profiling, immersion, mapping, coating, binder, migration
Other note
Parts
- Vyörykkä J., Halttunen M., Iitti H., Tenhunen J., Vuorinen T. and Stenius P., 2002. Characteristics of immersion sampling technique in confocal Raman depth profiling. Applied Spectroscopy 56, number 6, pages 776-782.
- Vyörykkä J., Paaso J., Tenhunen M., Tenhunen J., Iitti H., Vuorinen T. and Stenius P., 2003. Analysis of depth profiling data obtained by confocal Raman microspectroscopy. Applied Spectroscopy 57, number 9, pages 1123-1128.
- Vyörykkä J., Bousfield D. W. and Vuorinen T., 2004. Confocal Raman microscopy: a non destructive method to analyze depth profiles of coated and printed papers. Nordic Pulp and Paper Research Journal 19, number 2, p. 218.
- Vyörykkä J., Juvonen K., Bousfield D. W. and Vuorinen T., 2004. Raman microscopy in lateral mapping of chemical and physical composition of paper coating. Tappi Journal 3, number 9, p. 19.
