Provided are bicomponent fibers with improved curvature. The bicomponent fibers comprise a first polymer region or first region and a second polymer region or second region. The first region according to embodiments of the present disclosure comprises an ethylene/alpha-olefin interpolymer and has a light scattering cumulative detector fraction (CDF.sub.LS) of greater than 0.1200, wherein the CDF.sub.LS is computed by measuring the area fraction of a low angle laser light scattering (LALLS) detector chromatogram greater than, or equal to, 1,000,000 g/mol molecular weight using Gel Permeation Chromatography (GPC). The second region comprises a polyester. The bicomponent fibers can be used for forming nonwovens.

Provided are bicomponent fibers with improved curvature. The bicomponent fibers comprise a first polymer region or first region and a second polymer region or second region. The first region according to embodiments of the present disclosure comprises an ethylene/alpha-olefin interpolymer and has a light scattering cumulative detector fraction (CDF.sub.LS) of greater than 0.1200, wherein the CDF.sub.LS is computed by measuring the area fraction of a low angle laser light scattering (LALLS) detector chromatogram greater than, or equal to, 1,000,000 g/mol molecular weight using Gel Permeation Chromatography (GPC). The second region comprises a polyester. The bicomponent fibers can be used for forming nonwovens.

An object of the present invention is to provide a makeup brush bristle material and a makeup brush bristle material assembly, both made of synthetic resin, as well as a makeup brush using such bristle material or bristle material assembly, all suitable for applying both powder cosmetics and liquid cosmetics, or more specifically, offering good uptake and release properties with respect to powder or liquid cosmetics. As a solution, a makeup brush bristle material is provided that comprises S-twisted or Z-twisted core-sheath complex monofilaments whose core part is constituted by synthetic resin A and sheath part is constituted by synthetic resin B that differs in type from synthetic resin A, characterized in that the cross-section of the core-sheath complex monofilaments in the direction orthogonal to the axis of fiber has a cocoon shape.

An object of the present invention is to provide a makeup brush bristle material and a makeup brush bristle material assembly, both made of synthetic resin, as well as a makeup brush using such bristle material or bristle material assembly, all suitable for applying both powder cosmetics and liquid cosmetics, or more specifically, offering good uptake and release properties with respect to powder or liquid cosmetics. As a solution, a makeup brush bristle material is provided that comprises S-twisted or Z-twisted core-sheath complex monofilaments whose core part is constituted by synthetic resin A and sheath part is constituted by synthetic resin B that differs in type from synthetic resin A, characterized in that the cross-section of the core-sheath complex monofilaments in the direction orthogonal to the axis of fiber has a cocoon shape.

A polymer body includes a first thermoplastic polymer, and a second thermoplastic polymer. The first thermoplastic polymer and the second thermoplastic polymer form a continuous solid structure. The first thermoplastic polymer forms an external supporting structure that at least partially envelops the second thermoplastic polymer. A first flow temperature of the first thermoplastic polymer is at least 10° C. higher than a second flow temperature of the second thermoplastic polymer. The first thermoplastic polymer may be removable by exposure to a selective solvent.

A polymer body includes a first thermoplastic polymer, and a second thermoplastic polymer. The first thermoplastic polymer and the second thermoplastic polymer form a continuous solid structure. The first thermoplastic polymer forms an external supporting structure that at least partially envelops the second thermoplastic polymer. A first flow temperature of the first thermoplastic polymer is at least 10° C. higher than a second flow temperature of the second thermoplastic polymer. The first thermoplastic polymer may be removable by exposure to a selective solvent.

A preparation method of self-crimping elastic combined filament yarns for knitting is disclosed, wherein the combined filament yarns are extruded from the same spinneret; a first fiber-forming polymer melt is divided into two ways, one is directly extruded after distribution; and the other is extruded after distribution by side-by-side composite spinning together with a second fiber-forming polymer melt; the first fiber-forming polymer and the second fiber-forming polymer are compatible or partially compatible; on the same spinneret, a ratio of the number of spinneret holes m for direct extrusion to the number of spinneret holes n for extrusion after distribution by side-by-side composite spinning is 1:(5-10); the self-crimping elastic combined filament yarns for knitting are prepared according to specific spinning processes, wherein the combined filament yarn mainly comprises a first fiber-forming polymer monofilament and a first/second fiber-forming polymer side-by-side composite monofilament; wherein the monofilament crimping directions are randomly distributed.

A preparation method of self-crimping elastic combined filament yarns for knitting is disclosed, wherein the combined filament yarns are extruded from the same spinneret; a first fiber-forming polymer melt is divided into two ways, one is directly extruded after distribution; and the other is extruded after distribution by side-by-side composite spinning together with a second fiber-forming polymer melt; the first fiber-forming polymer and the second fiber-forming polymer are compatible or partially compatible; on the same spinneret, a ratio of the number of spinneret holes m for direct extrusion to the number of spinneret holes n for extrusion after distribution by side-by-side composite spinning is 1:(5-10); the self-crimping elastic combined filament yarns for knitting are prepared according to specific spinning processes, wherein the combined filament yarn mainly comprises a first fiber-forming polymer monofilament and a first/second fiber-forming polymer side-by-side composite monofilament; wherein the monofilament crimping directions are randomly distributed.

A type of side-by-side self-crimping elastic fiber and preparation method thereof are disclosed. The preparation method includes distributing compatible or partially compatible first fiber-forming polymer melts and second fiber-forming polymer melts, then the fiber is extruded from first spinneret holes and second spinneret holes on the same spinneret. The first fiber-forming polymer melts and the second fiber-forming polymer melts flow into the first spinneret holes through first and second distribution holes, and flow into the second spinneret holes through third and fourth distribution holes, wherein the four distribution holes are cylindrical holes of equal height, the ratio of the diameter of the first distribution holes to the diameter of the second distribution holes is (1.10-1.20):1, and the ratio of the diameter of the third distribution holes to the diameter of the fourth distribution holes is 1:(1.10-1.20).

A type of side-by-side self-crimping elastic fiber and preparation method thereof are disclosed. The preparation method includes distributing compatible or partially compatible first fiber-forming polymer melts and second fiber-forming polymer melts, then the fiber is extruded from first spinneret holes and second spinneret holes on the same spinneret. The first fiber-forming polymer melts and the second fiber-forming polymer melts flow into the first spinneret holes through first and second distribution holes, and flow into the second spinneret holes through third and fourth distribution holes, wherein the four distribution holes are cylindrical holes of equal height, the ratio of the diameter of the first distribution holes to the diameter of the second distribution holes is (1.10-1.20):1, and the ratio of the diameter of the third distribution holes to the diameter of the fourth distribution holes is 1:(1.10-1.20).