Folding Endurance and Tensile Strength of Paper

Abstract

Two equations are presently used to relate folding endurance to the load on the test strip Neither of these contains the initial tensile strength of the paper as a term, though tensile strength greatly influences folding resistance. An equation is derived which relates initial tensile, load and folding endurance. The three equations are compared using data from Goldberger and Rhyne. Schmidt's equation for the change in tensile strength as folding proceeds is discussed and an alternative relation is given. A unit is suggested for the tensile folding fatigue, TFF, of paper. The effect of paper thickness on folding endurance is considered.