Can the transmittance of PC mechanical windows be maintained above 90% for a long time?

    In the fields of industrial equipment, intelligent instruments, etc., PC mechanical windows bear the dual responsibility of protecting internal components and ensuring observation clarity. The long-term stability of their transmittance directly affects the effectiveness of equipment use. But can the transmittance of PC mechanical windows be maintained above 90% for a long time? This depends on the synergistic effect of multiple factors such as material selection, process control, and usage maintenance.

    The PC material itself has light transmission properties close to glass. The initial light transmittance of high-quality PC raw materials can reach around 90%, which lays the foundation for maintaining high light transmittance in the long term. However, ordinary PCs have inherent shortcomings, as the ester groups and benzene rings in their molecular structure are sensitive to ultraviolet radiation. Prolonged exposure to light can lead to oxidation reactions, causing molecular chain breakage and the formation of yellow compounds, thereby reducing light transmittance. Experiments have shown that after 3-5 years of outdoor use, the transmittance of untreated PC boards may decrease by 15% -30%, and it is obviously impossible to maintain a level of over 90%.

    The breakthrough in material modification technology provides the possibility to solve this problem. Aging resistant PC can effectively block ultraviolet light and delay the rate of yellowing by adding UV absorbers and light stabilizers. In the 1000 hour UV aging test, the transmittance attenuation of aging resistant PC is much lower than that of ordinary PC. More importantly, the surface protection technology, UV coating can form a protective layer on the surface of PC, which can filter 99% of UV rays.

   The processing technology has a profound impact on the long-term stability of light transmittance. If there is internal stress during PC processing, it can lead to uneven orientation of molecular chains, which may not only cause birefringence but also deteriorate optical performance over time. In addition, high processing temperatures or impurities in raw materials may cause a decrease in transmittance. By optimizing the injection molding and extrusion processes, controlling the processing temperature within 300 ℃, and avoiding contact with metal ions such as copper and iron, the risk of material degradation can be reduced, ensuring initial light transmittance and long-term stability.

    The usage environment and maintenance methods are equally crucial. In coastal areas with high salt spray or industrial pollution environments, rainwater and chemical erosion can accelerate PC aging. In daily maintenance, using hard tools for cleaning can easily cause scratches and also reduce light transmittance. Choosing the appropriate protection level for the environment and using a soft cloth for cleaning can effectively prolong the maintenance time of high transparency state.

    In summary, whether the light transmittance of PC mechanical windows can be maintained above 90% for a long time depends on whether anti-aging modified materials and UV coating protection are used, whether internal stress is controlled through precision machining, and whether maintenance is carried out in combination with environmental characteristics. On the premise of meeting material standards, exquisite craftsmanship, and proper maintenance, PC mechanical windows can fully achieve this goal, providing guarantees for the long-term reliable operation of industrial equipment. With the continuous advancement of material technology, the maintenance period of high transmittance will continue to be extended.