差動トランスを用いた膨潤による紙の厚さ変化の短時間連続測定

抄録

As for mechanism of liquid penetration, Lucas-Washburn's equation has been applied for years. Oil penetration is sure to be suited to this equation. But, water tends to deviate from it, which was confirmed also by the authors with weakly-sized paper. One of the main reasons for this is swelling. Swelling means the phenomenon of increasing volume when the material absorbs liquid. In case of paper it actually appears as increase in thickness including structural change resulting from interfiber debonding.
In the present study, we aim at measuring rapid thickness increase of paper precisely. For this purpose an new system for measuring thickness change was experimentally created using a differential transforme How swelling is involved in liquid absorption mechanisms was discussed in comparison with the data obtained by traditional Cobb's method and the results showed that
1. Rapid increase in paper thickness just after contact with water was able to be measured continuously with newly-developed differential transformer system.
2. Capillary absorption following by swelling occurs for sized paper from the result of comparison between water absorption volume and thickness increase measured with a using a differential transforme system.
3. Thickness increase measured with a differential transformer system did not correspond to Bristow's curve because of difference in penetration way. Therefore, simultaneous measurement system of thickness and absorption volume is required.