Characterization of liquid permeation through fibrous structure by texture analysis.

• Novel method of measuring the uniformity of liquid penetration through fibrous porous materials was proposed. • Texture entropy and contrast were taken into account in the proposed method. • Correlations between the dynamics of liquid penetration and the examined texture parameters were found. • New parameters were introduced for better evaluation of the nature of the liquid flow through the porous material structure. The interaction of liquids with materials is an important factor influencing many technological processes and describing the quality of the material itself. However, characterization of the wetting and penetration of liquids phenomena through the materials of heterogeneous structure is a very difficult task. Paper is an example of such material. Paper sizing is one of the most important operations in paper technology. Its purpose is to reduce the wettability of the paper. The aim of the present study was to evaluate the suitability of the texture analysis to assess the uniformity of liquid penetration through the paper structure in terms of the degree of the paper sizing. As a result of the research, a new method of measuring was proposed based on dynamic changes in their texture parameters. For this purpose, such texture parameters as entropy and contrast were used. Characteristic points were determined on the curves of the dynamic changes of both parameters. It was proved that there is a correlation between the dynamics of liquid penetration through the paper structure and the examined texture parameters. It was found that the maximum value of entropy and contrast, the time of reaching both values, the points of inflection of the curves during their decrease, and the times by which these points were reached can be useful parameters that provide information about the nature of the liquid flow through the porous material structure. [ABSTRACT FROM AUTHOR]