THE MAKING METHOD OF FILTER MEDIA MATERIAL BY DIFFERENT PROPERTIES POLYMERS IN MELT-BLOWN

摘要

A filtering medium and a method for manufacturing the same are provided to improve the air permeability and the filtering efficiency of the filtering medium, by increasing the bulky property of a web obtained by complex-spinning two kinds of polymers having different melting points. A first thermoplastic polymer, which has a fiber forming performance, and a second thermoplastic polymer, which has a fiber forming performance and a lower melting point than the first thermoplastic polymer, are melt-blown through a spinning nozzle for melt-blown type complex spinning, thereby obtaining a melt-blown complex spinning fiber. The melt-blown complex spinning fiber is hardened by air having a temperature lower than a glass transition temperature of the second thermoplastic polymer before reaching a collector. The hardened complex spinning fiber is collected by the collector, thereby forming a web. The web is thermally treated at a temperature between the melting point of the second thermoplastic polymer and the glass transition temperature to induce a shrinkage difference between the first thermoplastic polymer and the second thermoplastic polymer, thereby increasing the bulky property of the web.