| 摘要 |
<p>PROBLEM TO BE SOLVED: To provide a non-woven fabric excellent in thermoforming property, capable of excellently and easily forming into a formed filter, reduced in the cost and improved in profitability. SOLUTION: This nonwoven fabric for filter is constituted of a fiber containing >=20% adhesive fiber melting at 100-220 deg.C and the balance fiber to be stuck having a m.p. >=30 deg.C higher than that of the adhesive fiber. The nonwoven fabric for filter is a density gradient type nonwoven fabric formed by laminating >=2 layers of the fiber layers so as to decrease the average denier from the flow-in side towards the flow-out side of a treating fluid and tangling the structural fibers with each other by needle-punching from the finer fiber layer side, the fiber layer in the fluid flow-in side is controlled to have 4-12d average denier of the structural fiber and to have 95-99% porosity, the fiber layer of the flow-out side is controlled to have 0.6-03d average denier of the structural fiber and to have 0.07-0.35g/cc fiber density and the fiber to be stuck is stuck to each other with the adhesive fiber by heating each fiber layer constituting the nonwoven fabric at a temp. equal to above the melting starting temp. of the adhesive fiber.</p> |
