1.Bakelite material composition
Phenolic resin content: the main components of insulating bakelite board are phenolic resin and wood flour. The content of phenolic resin has an important effect on temperature resistance. Higher phenolic resin content usually improves the temperature resistance of bakelite boards. Because phenolic resin itself has better thermal stability, the benzene ring structure in its molecular structure provides better heat resistance. At high temperatures, the benzene ring is able to resist a certain degree of thermal decomposition, allowing bakelite panels to withstand higher temperatures.
Influence of additives: In addition to phenolic resins and wood flour, some other additives are sometimes added to improve the performance of bakelite panels. For example, the addition of some heat-resistant inorganic fillers, such as aluminum oxide and mica powder, can improve the high-temperature resistance of bakelite panels. These inorganic fillers can form a stable structure at high temperatures, preventing heat transfer and further thermal decomposition of the material.
2. Bakelite manufacturing process
– Hot pressing temperature and time: In the process of manufacturing insulated bakelite boards, hot pressing is a key process link. The hot pressing temperature and time directly affect the internal structure and performance of bakelite panels. If the hot pressing temperature is too high or the time is too long, it may lead to excessive cross-linking of the phenolic resin, making the bakelite board brittle and hard, and although it may initially improve its temperature resistance, it is prone to cracks and other problems in long-term use, which affects the stability of the temperature resistance properties. On the contrary, if the hot pressing temperature is too low or the time is too short, the resin crosslinking is incomplete, the internal structure of the bakelite board is not close enough, it is easy to soften and so on at high temperatures, reducing the temperature resistance.
– Curing degree: the degree of curing is also one of the factors affecting temperature resistance. Proper curing can make the phenolic resin form a stable three-dimensional mesh structure and improve the heat resistance of bakelite board. Incompletely cured bakelite panels are susceptible to flow and decomposition of the uncured resin portion at high temperatures, resulting in a decrease in temperature resistance.
3. Bakelite board use environment
– Humidity: Environmental humidity has a significant effect on the temperature resistance of insulated bakelite boards. In a high humidity environment, Bakelite boards easily absorb moisture. When the temperature rises, moisture accelerates the hydrolysis reaction of phenolic resin, which destroys the structure of bakelite boards and thus reduces their temperature resistance. For example, in wet basements or outdoor electrical equipment, without good waterproofing measures, insulated bakelite panels are more likely to suffer from performance during temperature changes.
– Chemical Exposure: If insulated bakelite panels are exposed to environments with chemicals, such as acids, alkalis, or organic solvents, these chemicals may react chemically with the components of the bakelite panels. For example, acids may corrode the molecular structure of phenolic resins, and when exposed to high temperatures, the corroded portions are more likely to thermally decompose, resulting in reduced temperature resistance.
– Whether there is mechanical stress: in the process of use, mechanical stress will also affect the temperature resistance of bakelite panels. If a bakelite panel is subjected to large pressure, tension or bending forces at the same time and is in a high-temperature environment, its internal structure may be accelerated and damaged due to stress concentration. For example, in an electric motor subjected to high vibration and high temperatures, bakelite boards used as insulating separators may lose their temperature resistance more quickly due to the combined effects of mechanical stress and high temperatures.
