The rupture of paper is controlled not by the mean strength, but by the minimum strength regions in the sheet. The objective of this study was to determine whether the structure varied significantly from point to point and to attempt to correlate the structural features of paper with properties in a deterministic way. By using a new analytical method for the estimation of fibre orientation, a relatively strong correlation was observed between local variation in mean fibre orientation and the local strength of paper. In order to improve the correlation between local tensile strength and local structure by considering fibre orientation and bonding simultaneously, an effort was also made to develop a relative strength model. However, due to the difficulty of characterizing local variations in bonding, the current results are not entirely convincing.
Further study is necessary.
The microtensile testing process used in this study is illustrated in Figure 1.