PVC cable material is widely used in power transmission and other fields. Its aging performance is directly related to the service life and safety of the cable. Therefore, it is of great significance to deeply explore its aging performance test and the influence of environmental factors.
First of all, the aging performance test usually adopts the accelerated aging test method. Common thermal aging tests are to place the PVC cable material in an aging box at a specific temperature for a certain period of time and then detect the changes in its various performance indicators. For example, the aging degree of the material can be evaluated by measuring the tensile strength, elongation at break and other mechanical performance parameters before and after aging. With the increase of aging time, the molecular chain of the PVC cable material will undergo changes such as breaking and cross-linking, resulting in a decrease in mechanical properties.
Secondly, ultraviolet radiation is also an important environmental factor affecting the aging of PVC cable material. Cables used outdoors are exposed to sunlight for a long time, and ultraviolet rays will break the chemical bonds in the PVC molecules, causing the material to change color and become brittle. In the aging performance test, the UV aging test box can be used to simulate the ultraviolet radiation environment in sunlight to observe the changes in the appearance and mechanical properties of the cable material under different radiation intensities and times. Generally speaking, the greater the intensity of ultraviolet radiation and the longer the time, the faster the aging rate of PVC cable material.
Furthermore, the humidity environment cannot be ignored for the aging of PVC cable material. In a high humidity environment, moisture may penetrate into the cable material, which will hydrolyze some chemical bonds in the PVC molecules on the one hand, and promote the seepage or migration of some additives on the other hand, thereby accelerating aging. In the aging performance test, the test environment with different humidity conditions was set. The results showed that when the humidity was high, the electrical performance of the cable material decreased more significantly, such as the insulation resistance decreased. This is because moisture conducts electricity and destroys the insulation structure of the material.
In addition, the chemical environment also affects the aging rate. For example, cables may be exposed to chemicals such as acids and alkalis in some industrial areas. Acidic substances will corrode PVC cable material, and alkaline substances may cause it to undergo saponification reaction. In the aging test simulating the chemical environment, the cable material was immersed in acid and alkali solutions of different concentrations. It was found that the higher the concentration, the more serious the aging phenomenon, and the mechanical properties and chemical stability decreased sharply.
In addition, the synergistic effect of temperature and other environmental factors has a significant effect on the aging rate. In high temperature and high humidity environment, the aging speed of PVC cable material is much faster than that in a single high temperature or high humidity environment. Because high temperature accelerates molecular movement, making the material more sensitive to humidity, ultraviolet rays and chemicals, multiple factors promote each other and accelerate the aging process.
In practical applications, in order to slow down the aging of PVC cable material, corresponding measures can be taken according to its use environment. For example, in areas with strong ultraviolet rays, use cable materials with added ultraviolet absorbers; in high humidity or chemical pollution environments, strengthen the design of cable protective layers, etc.
A comprehensive understanding of the aging performance test methods of PVC cable material and the influence of different environmental factors on its aging rate will help optimize the formulation and production process of cable materials and improve the reliability and life of cables in different environments.
