Criteria for judging the degree of aging of ePTFE membrane

1. Mild aging
Color: The color of the membrane may slightly darken, but the overall color remains relatively uniform, without obvious color difference.
Surface roughness: The surface is slightly rough, but it feels fine when touched by hand, and does not affect the overall smoothness.
Cracks: There may be a very small number of fine cracks, which are short in length and sparsely distributed.
Micropore structure: The shape of the micropores is basically regular, the pore size is relatively uniform, and only a small number of micropores are slightly deformed or blocked.
2. Moderate aging
Color: The color changes more obviously, with a certain degree of yellowing or fading, and there may be obvious color difference in some parts.
Surface roughness: The surface roughness is enhanced, and the obvious granularity can be felt by hand.
Cracks: There are more fine cracks, the length of some cracks has increased, and the distribution is relatively dense.
Micropore structure: Some micropores are deformed, the unevenness of the pore size increases, and about 10% - 30% of the micropores are blocked.
3. Severe aging
Color: The color is seriously yellowed, darkened, and even black spots appear, with obvious color difference.
Surface roughness: The surface is very rough and uneven, which seriously affects the smoothness.
Cracks: Long and wide cracks appear, and even some membrane layers peel off.
Micropore structure: A large number of micropores are deformed and blocked, and the pore size distribution is extremely uneven. More than 50% of the micropores lose their original shape, which seriously affects the breathability and waterproof performance.
4. Severe aging
Color: The film is dark brown or black and completely loses its original color.
Surface roughness: The surface is extremely rough, with obvious protrusions and depressions.
Cracks: The cracks are connected to each other to form larger cracks, and the integrity of the membrane is greatly damaged.
Micropore structure: The micropores are almost completely blocked or disappeared, and the breathability and waterproof performance are almost lost.