Measuring the degree of curl of paper

Abstract

I n a method frequently used to determine the tendency 'of paper to curl, !l measurement is made of the amount of curl of a small piece of the paper floating on water. The measurement is customarily made in terms of an arbitrarily chosen angle. The maximum curvature, however, is a more logical measure of curliness. An effort has been made to determine the maximum curvature of freely curling paper from m easurements made of the curling of paper in contact with water, and the new appar atus devised for the purpose is described. Measure-ments were made of the relative curliness of a number of lithographic papers. The correlation of cu rl with other related properties is discussed. The results of the measurement of curl agree reasonably weli with what is known about the behavior in use of the papers studied. CONTENTS P age