| 摘要 |
<p>The present invention provides composite filtering structures comprising fibres of nanometric sizes in the form of nanofibres 5 spatially distributed between fibres of micrometric sizes in the form of microfibers 6, in which filtering structures on the fibres of nanometric sizes 5 and on the fibres of micrometric sizes 6 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°, and preferably oriented at an angle of about 80° to about 100° to said fibre surface. The present invention further provides a method of obtaining such composite filtering structures by using of a melt-blown method in a process of fibre formation of thermoplastic polymers (3), which method comprising steps of: 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, and collecting the fibres, after their solidification at the fibre receiving plane (P) on a flat receiver, or on a rotating shaft and thus forming a mat of packed fibres providing a filtering structure. The said method further comprising a step of subjecting the said filtering structure to chemical etching by immersion in a concentrated solvent.</p> |
