The waterproof and breathable valve can achieve the seemingly contradictory functions of waterproofing and ventilation, and behind this lies its ingenious working principle. This principle is based on the special physical properties of the breathable membrane and the structural design of the entire valve.

The nanoscale microporous structure of the breathable membrane is the key. Due to thermal motion, gas molecules are in a constant state of random motion. The diameter of these molecules is much smaller than the size of the micropores, and they have sufficient kinetic energy. Therefore, they can easily pass through the micropores, enabling gas exchange between the inside and outside of the equipment and achieving the purpose of ventilation.

Liquid water molecules, however, are different. On the one hand, there are strong hydrogen - bonding forces between water molecules, causing them to tend to aggregate together to form larger clusters. On the other hand, the size of these clusters is larger than the micropores of the breathable membrane, preventing them from passing through. In addition, surface tension also comes into play. When water comes into contact with the breathable membrane, the surface tension causes water to form droplets on the membrane surface, further preventing water penetration and thus achieving the waterproof function.

When the internal pressure of the equipment is higher than the external pressure due to factors such as temperature increase or chemical reactions, under the action of the pressure difference, gas is discharged from the inside through the breathable valve along the concentration gradient to balance the internal pressure. Conversely, when the external pressure is higher than the internal pressure, external gas will enter the inside. At the same time, the outer shell of the waterproof and breathable valve protects the breathable membrane, enabling it to work normally in harsh environments. This clever design based on physical principles enables the waterproof and breathable valve to reliably achieve the dual functions of waterproofing and ventilation under various complex conditions.