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Online quality evaluation of tissue paper structure on new generation tissue machines

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Details

Original languageEnglish
Pages (from-to)133-141
Number of pages9
JournalNordic Pulp and Paper Research Journal
Volume33
Issue number1
DOIs
Publication statusPublished - 26 Mar 2018
Publication typeA1 Journal article-refereed

Abstract

At present, the tissue paper manufacturing is mostly based on the dry crepe technology. During the last decade, the manufacturers have introduced new tissue machines concepts that increase the softness, bulk, and absorption capacity. Such machines produce a strong regular three-dimensional (3D) structure to the sheet before the Yankee cylinder. At present, the quality of the 3D structure is not evaluated, or it is evaluated only subjectively at the mill. This is mostly because of the difficulties to separate reliably the regular 3D pattern from other variations. This paper introduces a frequency analysis based method which separates the surface profile variances in tissue paper to the creping, to the regular 3D pattern and to the residual variation. The 3D surface profiles and their variances were determined online with the photometric stereo method. We show that the introduced analysis method evaluates the variance portions reliably and the results are consistent with the visual perception of the 3D surfaces. In one particular product, the regular 3D pattern explains 74 % of total surface variance; the creping explains 10 % and residual variations 16 %. Furthermore, the creping and residual variances are quite stable over time whereas the variance of the regular 3D pattern fluctuates significantly.

ASJC Scopus subject areas

Keywords

  • frequency analysis, photometric stereo, regular 3D structure, tissue paper

Publication forum classification

Field of science, Statistics Finland