Rubber aging test

Aging is one of the main reasons for the deterioration of rubber properties. Due to the different formulations and use conditions of the products, the aging process is different, so it is necessary to measure and evaluate through the aging test to evaluate the degree of rubber aging and its impact on performance. The aging test is a test method and test method used to evaluate the change of rubber properties before and after a certain period of time under external conditions (generally, performance decline or deterioration). Natural aging test The rubber test piece is placed in the outdoor natural environment in the tensile state, and after a long time of sun and rain, the performance changes before and after are observed, measured and compared. Although this method has high fidelity and strong simulation of the actual situation, it is often time-consuming. Generally, it is suitable as an auxiliary reference, but it is impossible to complete the test in a short time, and it is impossible to draw a conclusion. Accelerated aging test In order to obtain aging test data in a relatively short period of time, it is necessary to use an accelerated aging test. Strengthen the test conditions, speed up the aging process, greatly shorten the test cycle, and obtain the test results-aging data faster. Such test items include: Oven heating aging test, referred to as thermal aging test, is the most widely used method at present. The test equipment used was a heated oven. Heating temperature and time can be set. The test piece is hung on the rotating film rack in the box. After the test, take out the test piece, measure its performance, compare it with the data before aging, calculate the aging coefficient, and measure the degree of damage. For example, if the tensile strength of a compound before heat aging is 20MPa, and it is reduced to 12MPa after heat aging, the aging coefficient is 0.6. Weather aging test Simulate the environmental conditions when used outdoors, and perform accelerated aging test in the box on the sample. The test device can reproduce the climatic conditions encountered in actual use, such as sunlight (replaced by light irradiation) and rain (replaced by water spray). Therefore, the accelerated aging test light source under simulation and simulation conditions adopts ultraviolet light or carbon arc. lamp. The test time can be in 10—Adjust within 1000h. After the test, in addition to measuring the physical properties, it is also necessary to observe the surface cracks. Ozone aging test is used to investigate the damage degree of ozone to rubber. The test device is a closed ozone aging box. There is an ozone generator inside, which generates a certain concentration of ozone through a mercury lamp. The test piece is subjected to a certain tensile deformation during the test. After a certain period of time, the crack depth on the surface of the sample was observed to judge the ozone resistance level of the rubber compound. Oxygen aging test The test piece was placed in a metal bullet-shaped airtight container, filled with oxygen, and tested under heating and pressure. The temperature is generally heated to 70 ~ C. Oxygen pressure is kept at 0.6—0.7MPa, the duration is optional in 24, 48, 72h. After the specified time, park at room temperature for 16—After 96h, the performance changes before and after the test were compared. Company website: https://www.orksealing.com/