Accelerated aging test for paper

Abstract

A series of Government bond and ledger papers was studied with reference to certain properties that appear to be related to permanence. These papers, purchased on specification, were assumed to be representative of the different commercial grades. A thorough study was made of the physical and chemical properties of the papers as well as of their behavior when exposed to various accelerated aging tests. The results indicate the feasibility of classifying papers by means of suitable chemical, strength, and accelerated aging tests. The chemical tests include tests for fiber purity and noncellulosic impurities, such as acid and rosin, used in sizing. The fiber purity, which is indicated by the alpha cellulose content and copper number, was found to bear an important relation to the stability of the papers. The accelerated aging test, which consists in exposing the papers to a temperature of 100° C. for 72 hours, and then determining the effect produced on the chemical and physical properties, appears to arrange the papers in about the same order of stability that would be expected on natural aging. A comparison of the results of the above-mentioned aging treatment with results obtained by using more nearly normal conditions (60° C. for 860 hours, and sunlight exposures) shows that they all classified the papers in the same order of stability. These two findings are evidence that the more drastic treatment, which is desirable in respect to convenience and rapidity, gives results in line with more normal aging effects.