Nylon water-vapor transmission rate

PLA fibers are environment-friendly material and the demand for PLA fibers as a substitute for the present synthetic fibers has been growing greatly in recent years. Furthermore, high water vapor transmission rate of PLA makes it a good candidate for fabricating fibers used in garments [e.g., shirts, dresses, underwear, shoes, etc.] to improve their "breathability. While PLA fibers are not as wettable as cotton, they exhibit much greater water vapor transmission than aromatic polyesters or nylon fibers. 

There are substantial differences in the rates at which water vapor and other gases can permeate different plastics. For instance, PE is a good barrier for moisture or water vapor, but other gases can permeate it rather readily. Nylon, on the other hand, is a poor barrier to water vapor but a good one to other vapors. The permeability of plastic films is reported in various units, often in grams or cubic centimeters of gas per 100 in.2 per mil of thickness (0.001 in.) of film per twenty-four hours. The transmission rates are influenced by such different factors, as pressure and temperature differentials on opposite sides of the film. 

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