COMPOSITE FILTERING STRUCTURES AND A METHOD FOR OBTAINING COMPOSITE FILTERING STRUCTURES

摘要

Composite filtering structures comprising nanofibres spatially distributed between microfibers, wherein on the nanofibers and on the microfibers a palisade of protrusions of nanometric sizes in the form of nano-protrusions is produced, which palisade comprises nano-protrusions oriented with respect to the fibre surface at an angle ranging from about 70° to about 120°. A method of obtaining such composite filtering structures by a method that includes feeding a thermoplastic material from an extruder to at least one fibre formation die, stretching formed fibres coming out from the die, which fibres being still in a molten phase, to smaller sizes by a stream of hot air flowing tangentially to the fibres, collecting the fibres after their solidification and thus forming a mat of packed fibres providing a filtering structure , and subjecting the filtering structure to chemical etching.