초록

The present invention provides a self-supporting laminate filter medium having an electret lofty spunbond web and an electret microfiber web, wherein the spunbond web has a density between about 0.01 g/cm.sup.3 and about 0.1 g/cm.sup.3.

대표청구항 ▼

[ What is claimed is:] [1.] A method of making a laminate filter media comprising:forming a multicomponent spunbond fiber web having at least a first thermoplastic polymer component and a second thermoplastic polymer component wherein said first thermoplastic polymer component has a higher melting p

[ What is claimed is:] [1.] A method of making a laminate filter media comprising:forming a multicomponent spunbond fiber web having at least a first thermoplastic polymer component and a second thermoplastic polymer component wherein said first thermoplastic polymer component has a higher melting point than said second thermoplastic polymer component;through-air bonding said multicomponent spunbond fiber web wherein said multicomponent spunbond fiber web has inter-fiber bonds at fiber cross-over points distributed substantially throughout said multicomponent spunbond fiber web and wherein the density of said bonded multicomponent spunbond fiber web is between about 0.01 and 0.1 g/cm.sup.3 ;electret treating said bonded multicomponent spunbond fiber web wherein said multicompnent spunbond fibers retain a charge;forming a microfiber web;electret treating said microfiber web wherein said microfiber web retains a charge; andfixedly attaching said bonded multicomponent web to said microfiber web to form a contiguous multilayer laminate wherein the central portion of said multilayer laminate has a substantially uniform thickness and air permeability.