Abstract: The present invention provides a thermally-bonded nonwoven fabric that is made from a web which comprises from 100 to 5 percent by weight of multiconstituent fibers. The multiconstituent fibers are composed of highly dispersed blends of at least two different immiscible thermoplastic polymers and have a dominant continuous polymer phase with at least one noncontinuous phase dispersed therein. The noncontinuous phase exists as an elongated fibrillar polymer domain oriented generally in the direction of the fiber axis. No single polymer domain cross-section of the noncontinuous phase or phases is larger than 0.1% of the cross-sectional area of the fiber. The polymer of the noncontinuous phase or phases has a Polymer Melt Temperature (PMT) at least 30.degree. C. below the PMT of the continuous phase. The fiber is configured such that the noncontinuous phase or phases occupy a substantial portion of the fiber surface.

Abstract: A nonwoven filamentary web having high loft is produced by extruding a molten thermoplastic polymer or polymer blend through a spinneret to form continuous filaments while maintaining extrusion conditions which induce melt-fracture of the extrudate; attenuating the thus extruded melt-fractured filaments to obtain filamentary material having a crimped structure; and depositing the melt-fractured filamentary material on a collection surface and forming a web therefrom.

Abstract: The present invention provides a thermally-bonded nonwoven fabric that is made from a web which comprises from 100 to 5 percent by weight of multiconstitutent fibers. The multiconstituent fibers are composed of highly dispersed blends of at least two different immiscible thermoplastic polymers and have a dominant continuous polymer phase with at least one noncontinuous phase dispersed therein. The noncontinuous phase exists as an elongated fibrillar polymer domain oriented generally in the direction of the fiber axis. No single polymer domain cross-section of said noncontinuous phase or phases is larger than 0.1% of the cross-sectional area of said fiber. The polymer of the noncontinuous phase or phases has a Polymer Melt Temperature (PMT) at least 30.degree. C. below the PMT of the continuous phase. The fiber is configured such that the noncontinuous phase or phases occupy a substantial portion of the fiber surface.

Abstract: A fiber made of pitch having a percent elongation of about 2 percent or greater is made by melt spinning an optically isotropic pitch to form a fiber typically in the range of about 5 to about 50 microns diameter, treating the fiber with an oxidizing atmosphere, subsequently removing a certain portion of the oxidant thereby reducing the weight of the fiber, with the optional post-treatment step of repetitively stretching in the elastic range short of breakage to increase the percent elongation.

Abstract: A fiber made of pitch is disclosed. In the preferred and illustrated embodiment, the fiber has a percent elongation of about 2 percent or greater. This fiber is made by melt spinning an optically isotropic pitch to form a fiber typically in the range of about 5 to about 50 microns diameter, treating the fiber with an oxidizing atmosphere, subsequently removing a certain portion of the oxidant thereby reducing the weight of the fiber, with the optional post-treatment step of repetitively stretching in the elastic range short of breakage to increase the percent elongation.

Abstract: A porous thermoformable heat sealable nonwoven fabric that is constructed by carding a bicomponent polymeric fiber and then heating the resulting fibrous web to cause bonding. The polymeric components of the bicomponent fiber have crystalline melting points that differ by at least 30.degree. C. The bicomponent fiber has a staple length ranging from 1.5" to 3.0" and a staple elongation-to-break of at least 30%.