ABSTRACT
IV. Sources of Error in the Evaluation of the Bending Stiffness of Paper 240 A. Effect of Deviations from Hooke’s Law 240 B. Effect of Slope of the Deflected Beam 243 C. Effect of Interlaminar Shear 243
D. Effects of Deformation of the Paper in the Clamp in the Two-Point Method 245
E. Discussion 246
V. Calculation of Bending Stiffness of Multi-Ply Sheets 247 A. General Background 247 B. Procedure for the Calculation of Bending Stiffness 248
VI. Influence of Pulp and Papermaking Variables on Bending Stiffness 250 A. Bending Stiffness of a Single-Ply Sheet 250 B. Bending Stiffness of a Multi-Ply Sheet 251
Appendix 253
References 255
I. INTRODUCTION
Bending stiffness is an important property for both paper and paperboard in both converting and end-use situations. For thin papers, high bending stiffness is extremely important during converting operations such as feeding in fast presses, folders, copying machines, and sack-forming machines. On the other hand, low bending stiffness is a requirement in, for instance, label papers and papers in books and magazines in order to obtain good conformability and folding proper ties [11].
