Fine fiber media layer
Disclosed are improved polymer materials. Also disclosed are fine fiber materials that can be made from the improved polymeric materials in the form of microfiber and nanofiber structures. The microfiber and nanofiber structures can be used in a variety of useful applications including the formation of filter materials.
1. A filter media comprising a fine fiber layer and a filtration substrate layer, the fine fiber layer comprising a fiber size comprising a diameter of about 0.01 to 0.5 micron, the fine fiber comprising a polyvinylidene fluoride or comprising a copolymer comprising hexafluoropropylene and vinylidene fluoride, the layer having a thickness no greater than 30 microns and a basis weight of about 0.5 to 150 g-m −2 .
2. The media of claim 1 wherein after exposure to air at 140° F. and 100% relative humidity for 16 hours at least 50% of the fiber remains substantially unchanged for filtration.
3. The media of claim 1 wherein the fiber size comprises a diameter of 0.1 to 0.5 microns.
4. The media of claim 1 wherein the fiber size comprises a diameter of 0.01 to 0.2 microns.
5. The media of claim 1 wherein the filtration substrate layer comprises a woven or non-woven substrate.
6. The media of claim 5 wherein the non-woven substrate comprises a fiber selected from cellulose, glass, a synthetic polymer, metal, and combinations thereof.
7. The media of claim 1 wherein the substrate layer comprises spun bonded synthetic polymeric non-woven fabric.