For several years, waterproof breathable fabrics have been developed for use in garments to provide protection to the human body. The final properties of that fabric are defined by all of the materials used in the assembly of the compose material and by its after treatment. Membrane technologies and advanced polymers and materials have been developed to meet specific performance criteria for outdoor activities as well as occupational and industrial uses. Electrospun nanofibers are being considered for a variety of performance apparel applications where their unique properties contribute to product functionality. Those properties include high surface area, small fiber diameter, potential to incorporate active chemistry, filtration properties, layer thinness, high permeability, and low basis weight.
Performance apparel fabrics are evaluated on the performance of the composite material. Attributes most frequently evaluated include:
- Water resistance: Water column measurement
- Breathability: Air permeability
- Water Vapor Transmission: Diffusion of moisture through the material
- Windproof: Blocking of the entry of outside air into the garment
- Resistance to wear: Durability
To meet the diverse range of end uses and consumer needs for different types of activities, it is necessary to develop materials that offer different levels of breathability and water resistance. Electrospun nanofiber webs can be engineered with a desired porous structure and a range of polymers. The unique combination of high specific surface area, flexibility, low basis weight, and porous structure allows manufacturers to optimize the water resistance level, air permeability and water vapor transmission rate.
Performance characteristics of waterproof breathable material