Principles and Methods of Aging Test of Rubber and Plastic Products In the process of storage and use and manufacturing process of rubber or rubber products, due to the physical, chemical, and biological effects, their use performance is gradually reduced, even losing their use value. This phenomenon is called aging. Therefore, it is of great significance to determine the aging properties of rubber, to estimate the service life of products, and to study the aging and protection efficiency of rubber.
Rubber aging tests can be divided into two categories according to test conditions:
Natural aging test methods: These include atmospheric static weathering tests, atmospheric accelerated weathering tests, natural storage aging tests, natural media aging tests, and natural biological aging tests. The natural aging test method, although it can obtain more reliable test results, the method is simple, but the aging rate is slow, the test cycle is long, can not meet the needs of scientific research and production.
Artificial accelerated aging test: Including thermal aging, ozone aging, photo-aging, artificial weathering, photo-ozone aging, and biological aging. It is a common aging method in production and scientific research.
1 hot air aging test
The hot air aging test is one of the most common thermal oxidation tests. It is a method in which a rubber sample is exposed to hot air at a normal pressure and a prescribed temperature, and the change in its physical and mechanical properties is measured after a certain period of time.
GEER Gil Type Thermal Ageing Tester Model: AG-1100
2 Rubber Ozone Aging Test
Because the chemical activity of ozone is much higher than that of oxygen, the rubber products have a longer aging time, which causes the molecular chains to break, and cracks occur on the surface under the action of stress, resulting in loss of use value of rubber.
The ozone aging test is to measure the change of physical and mechanical properties or to observe the earliest occurrence of ozone cracking under the effect of static or dynamic tensile stress of a stool sample after a certain temperature and ozone concentration.
The static tensile strain test specimens were exposed to air and a constant temperature test chamber containing a constant ozone concentration, and the cracking of the specimens was examined as scheduled.
Three methods for evaluating ozone cracking under selected ozone concentration and test temperature conditions
A. At a specified time and under specified strain, check for cracks and if necessary, determine the degree of cracking.
B. Under the specified tensile strain, the time when the crack first appeared was measured.
C. Critical strain was measured for the specified time.
The critical strain refers to the maximum tensile strain at which the ozone cracking does not occur after a predetermined period of time when the rubber is exposed to air containing a certain concentration of ozone at a given temperature.

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