Provided is a melt-blown nonwoven fabric including a propylenic polymer that shows at least one peak top at a position of a molecular weight of 20,000 or higher and at least one peak top at a position of a molecular weight of less than 20,000 in a discharge curve obtained by gel permeation chromatography, and has an intrinsic viscosity [] of from 0.50 (dl/g) to 0.75 (dl/g).

A melt blowing system for the manufacturing of pleatable/moldable nonwoven fabrics includes a collector positioned to receive a plurality of fibers, a first die in fluid communication with a first liquid polymer supply having a melt flow index of about 500 or lower, and a second die in fluid communication with a second liquid polymer supply having a melt flow index of about 500 or higher. The first die has a concentric air design, includes a plurality of spinneret nozzles facing the collector surface, and is configured to draw a first plurality of fibers. The second die includes a plurality of spinneret nozzles having smaller capillary diameter than those of the first die and is positioned to draw a second plurality of fibers such that the first and second pluralities of fibers form a co-mingled nonwoven web with varying fiber diameters on the collector surface.

A melt blowing system for the manufacturing of pleatable/moldable nonwoven fabrics includes a collector positioned to receive a plurality of fibers, a first die in fluid communication with a first liquid polymer supply having a melt flow index of about 500 or lower, and a second die in fluid communication with a second liquid polymer supply having a melt flow index of about 500 or higher. The first die has a concentric air design, includes a plurality of spinneret nozzles facing the collector surface, and is configured to draw a first plurality of fibers. The second die includes a plurality of spinneret nozzles having smaller capillary diameter than those of the first die and is positioned to draw a second plurality of fibers such that the first and second pluralities of fibers form a co-mingled nonwoven web with varying fiber diameters on the collector surface.

Provided is a crimped fiber constituted of the following first component and second component, wherein the first component is a propylene-based resin composition containing a propylene-based polymer (1-A) in which a melting point (Tm-D) obtained under a specified condition exceeds 120 C. and a propylene-based polymer (1-B) satisfying the conditions that (a) a weight average molecular weight (Mw) is 10,000 to 200,000, (b) a molecular weight distribution (Mw/Mn) is less than 4.0, and (c) a melting point (Tm-D) obtained under a specified condition is 0 to 120 C.; and the second component is a propylene-based polymer (2) in which a melt flow rate (MFR) under the foregoing measurement condition is 1 g/10 min or more and 2,000 g/10 min or less, and a melting point (Tm-D) observed under the foregoing measurement condition by using a differential scanning calorimeter (DSC) exceeds 120 C., or a propylene-based resin composition containing the propylene-based polymer (2).

Provided is a crimped fiber constituted of the following first component and second component, wherein the first component is a propylene-based resin composition containing a propylene-based polymer (1-A) in which a melting point (Tm-D) obtained under a specified condition exceeds 120 C. and a propylene-based polymer (1-B) satisfying the conditions that (a) a weight average molecular weight (Mw) is 10,000 to 200,000, (b) a molecular weight distribution (Mw/Mn) is less than 4.0, and (c) a melting point (Tm-D) obtained under a specified condition is 0 to 120 C.; and the second component is a propylene-based polymer (2) in which a melt flow rate (MFR) under the foregoing measurement condition is 1 g/10 min or more and 2,000 g/10 min or less, and a melting point (Tm-D) observed under the foregoing measurement condition by using a differential scanning calorimeter (DSC) exceeds 120 C., or a propylene-based resin composition containing the propylene-based polymer (2).

Nonwoven webs including one or more semi-continuous filaments made of a mixture including from about 50% w/w to about 99% w/w of at least one crystalline polyolefin (co)polymer, and from about 1% w/w to about 40% w/w of at least one hydrocarbon tackifier resin. The at least one semi-continuous filament exhibits molecular orientation, and at least one of the crystalline polyolefin (co)polymer or the nonwoven web exhibits a Heat of Fusion measured using Differential Scanning Calorimetry of greater than 50 Joules/g. A process for making the semi-continuous filaments and nonwoven webs is also disclosed.

Nonwoven webs including one or more semi-continuous filaments made of a mixture including from about 50% w/w to about 99% w/w of at least one crystalline polyolefin (co)polymer, and from about 1% w/w to about 40% w/w of at least one hydrocarbon tackifier resin. The at least one semi-continuous filament exhibits molecular orientation, and at least one of the crystalline polyolefin (co)polymer or the nonwoven web exhibits a Heat of Fusion measured using Differential Scanning Calorimetry of greater than 50 Joules/g. A process for making the semi-continuous filaments and nonwoven webs is also disclosed.

Melt-blown webs having a widened process window and better barrier properties(3rd drop, cm H2O resp. mbar). The melt-blown webs are made from so-called controlled rheology propylene (CR-PP), which has been visbroken without the use of peroxide but with a specific type of visbreaking additive.

Melt-blown webs having a widened process window and better barrier properties(3rd drop, cm H2O resp. mbar). The melt-blown webs are made from so-called controlled rheology propylene (CR-PP), which has been visbroken without the use of peroxide but with a specific type of visbreaking additive.

The prepreg sheet, which is an intermediate of molded articles, has a nonwoven fabric having carbon fibers and thermoplastic resin fibers, wherein the prepreg sheet has a thickness expansion rate of 250% or less after being heated for 90 seconds at a temperature of the melting point of the thermoplastic resin fiber to the melting point+100 C.