Aging test of rubber materials in explosion-proof junction boxes

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Aging test of rubber materials in explosion-proof junction boxes: The rubber rings and sealing gaskets used in explosion-proof junction boxes must undergo aging tests. During manufacturing, storage, and use, these junction boxes are subject to various internal and external factors, which cause the physical and chemical properties as well as mechanical strength of the rubber to deteriorate over time, eventually rendering it unusable. This process of deterioration is known as rubber aging. Rubber aging is manifested by phenomena such as cracking, blistering, hardening, softening, pulverization, discoloration, and mold growth. To obtain aging test results as quickly as possible, artificial accelerated aging tests that simulate and intensify certain aging factors are widely used. The specific procedure for aging testing explosion-proof junction boxes involves placing the materials under test in an oven and heating them to 100°C for 168 hours; thereafter, they are exposed to room temperature for 24 hours. Next, they are placed in a low-temperature chamber at -10°C for 48 hours, after which they are again exposed to room temperature for 24 hours. After undergoing these aging tests, the Shore hardness of the explosion-proof junction boxes is measured, with any change in hardness (“hardening” or “softening”) not exceeding 20% of the value before treatment.