1. Bakelite board Short-term use
– In the normal operating temperature range (-40 ° C – 120 ° C), if the insulating bakelite board is only used for a short period of time, its temperature resistance generally does not decline significantly with time. For example, in some short-term operation of the experimental equipment or intermittent work of small electrical devices, as long as the temperature does not exceed the specified range each time the use of bakelite boards can be used in the process of many times to maintain a relatively stable temperature resistance. This is because in a short period of time, the molecular structure and chemical composition within the bakelite board does not have enough time for significant changes in its physical and chemical properties can be maintained in a stable state.
2. Bakelite boards Long-term in a high-temperature environment
– When insulated bakelite panels are subjected to high temperatures for a long period of time (close to or over 120°C), their temperature resistance will gradually decline. Prolonged exposure to high temperatures will cause the molecular chain of the phenolic resin to break gradually, and this destruction of the molecular structure is an irreversible process. With the breakage of the molecular chain, the resin will be further softened, and the mechanical strength of bakelite panels will continue to decrease, such as compressive strength and flexural strength will decrease year by year. At the same time, its insulating properties will also be affected, the insulation resistance will be reduced, the dielectric constant may increase, which may ultimately lead to a lower breakdown voltage. For example, in some industrial motors that have been working at high temperatures for a long time, if insulated bakelite boards are subjected to high temperatures for a long period of time as insulating spacers, after a few years of time, insulation failure may occur.
3. Bakelite boards in long-term low-temperature environment
– In a long-term low-temperature environment (below -40 ℃), although the insulating bakelite board’s temperature resistance decreases at a relatively slow rate, it will be affected to a certain extent. Prolonged exposure to low temperatures will cause the resin and wood powder and other components in bakelite boards to gradually lose their toughness and become more brittle and hard. When impacted by external forces, bakelite boards are more likely to crack or break. However, compared with the high-temperature environment, the decline in temperature resistance in low-temperature environments has less direct impact on its insulating properties, mainly on the destruction of mechanical properties. For example, in some outdoor electrical equipment in cold regions, if insulated bakelite panels are exposed to low temperatures for a long period of time, they are more likely to be damaged due to collisions during installation or maintenance.
4. Influence of other factors
– In addition to the temperature itself, other factors in the environment can also affect the rate of decline in the temperature resistance of insulated bakelite panels. For example, in a humid environment, moisture may penetrate into the interior of the bakelite board, and in a high-temperature environment, the presence of moisture accelerates the hydrolysis reaction of the resin, thereby accelerating the decline in the performance of the bakelite board. And in an environment where chemical corrosive substances are present, these chemicals may react chemically with the components of the bakelite board, further destroying its molecular structure and leading to a faster decline in the temperature resistance of the bakelite board when the temperature changes.
