NONWOVEN FABRIC FOR PLEATED FILTER AND PROCESS FOR PREPARING THE SAME

摘要

A nonwoven fabric for pleated filters comprising a core-sheath continuous filament of a polymer component having a high melting point as the core component and a polymer component having a low melting point as the sheath component, characterized in that the surface of the nonwoven fabric has a plurality of contact-bonded portions created by partial embossing and the weight per unit area, X (g/m<2>), of the nonwoven fabric and the bending resistance, Y (mgf), determined by the JIS L 1096 Gurley method satisfies the following relationship: Y/X<2> >/= 0.03 and X >/= 120; and a filter element comprising the nonwoven fabric for pleated filters as a filter medium. The nonwoven fabric can be prepared by pulling and stretching a continuous filament spun from a core-sheath composite spinneret, opening and depositing the filament onto a network material being moved, thereby forming a continuous filament web, preliminarily contact-bonding the web by means of a pair of heated flat rolls, and partially hot contact-bonding by means of a pair of emboss rolls. A high-performance nonwoven fabric for pleated filters can be provided which is free from the drawback of separation and has suitable rigidity, good fabricability into pleats and shape retention.