Material testing and product properties
- Why test pulp and paper?
- Fibre properties
- Papermaking properties of pulp
- Fluff pulps
- Chemical analysis of pulps
- General physical properties of paper and board
- Optical properties of paper
- End-use properties of printing papers
- End-use properties of packaging papers and boards
- Tissue papers
- Permanent papers
- Reliability of results in physical testing of pulp and paper
- Quality control at the mill
- Standardisation in pulp and paper testing
Opacity Opacity is a measure of a material’s ability to obstruct the passage of light. Sufficient opacity is important to prevent printed text from showing through in a harmful manner on the reverse side of a paper. The ISO standard 2471 determines the opacity: Opacity, % = (R0 ⁄ R∞) 100 (1) where
Authors & references
Edited by:
Petteri Maijanen, ABB
Original author:
Juhani Vaarasalo
Based on: Vaarasalo J., Optical properties of paper (Chapter 8). In: Levlin, J-E. & Sjöderhelm, L. (ed), Pulp and paper testing (Book 17), Papermaking Science and Technology. Jyväskylä. 1999. Fapet Oy. pp. 163-181.
References:
- Pauler, N., Paper Optics, 2nd Edition, AB Lorentzen & Wettre, Kista, 2012, p. 56.
- ISO 11664-2:2007(E)/CIE S014-2/E:2006 Joint ISO/CIE Standard: Colorimetry — Part 2: CIE Standard Illuminants
Videos
Exercises
This page has been updated 31.03.2021