The so-called durability of paper can also be said to be the life of paper. Because it involves the storage time of printed matter and books, but the natural aging of paper takes a long time, so the artificial rapid aging method is generally used to measure and infer the durability . As paper ages, both its structure and its elasticity change. In order to determine this hidden change, it is best to use a method that does not damage the paper itself, usually an artificial heat aging test. Temperature is the simplest, most important, and most easily repeatable factor to accelerate chemical changes. Put the paper in a certain temperature environment, and infer the durability of the paper according to the process of its change. Of course, the changes in paper properties under artificial heat aging conditions cannot be exactly the same as the corresponding changes in long-term storage of paper under natural conditions. Therefore, artificial thermal aging can only be regarded as an approximate simulation of natural aging.
The main equipment for the durability test is one or two high-quality Incubators with a blower system and an adjustable temperature and humidity device. According to a large number of experimental figures, the American National Bureau of Standards proposed that the artificial aging of paper in an Incubator at (105±0.5)°C for 3 days, 6 days, 12 days, and 24 days is equivalent to 25 years of storage under natural conditions. 50 years, 100 years, 200 years.
In order to show the performance of paper aging resistance, that is, the durability, it is generally expressed by the change (decline rate) of the physical and chemical performance indicators of paper before and after aging. The selected indicators are mainly: folding resistance, tearing degree, whiteness, copper price, viscosity, pH value, etc.