Abstract:
Meltblown nonwoven compositions and processes for forming them are described herein. In one or more embodiments, the invention is directed to meltblown nonwoven fabrics having at least one elastic layer, wherein the elastic layer comprises a propylene-based polymer having an MFR greater than about 25 g/10 min. Additionally, the propylene-based polymer comprises from about 5 to about 25 wt% of one or more C2 and/or C4-Ci2 a-olefms and has a triad tacticity greater than about 90% and a heat of fusion less than about 75 J/g. The present invention is also directed to processes for forming meltblown nonwoven fabrics comprising forming a molten propylene-based polymer having an MFR of at least about 25 g/10 min, forming fibers comprising the propylene-based polymer, and forming an elastic nonwoven layer from the fibers.
Abstract:
Provided is a propylene polymer composition comprising a neat polymer, a hydroxylamine ester compound and a plasticizer suitable for preparing low melt viscosity polymers useful in spinning, melt blowing, extruding and the like. Further provided are non-woven fabrics made from the composition. The fabrics exhibit superior drapeability, softness and handle. The polymer composition exhibits near-neat propylene polymer melt viscosity such that it can be readily pelletized for transport or use by an end user other than the composition manufacturer.
Abstract:
A blended polypropylene composition, fiber, and nonwoven articles made therefrom are provided. In one aspect, the blended polypropylene composition comprises a first polymer component having a molecular weight distribution of from 2.5 to 8, and a second polymer component having a molecular weight distribution of from 1.8 to 3. The frst polymer component has a melt flow rate of greater than 30 g/10 min. and the second polymer component has a melt flow rate of less than 40 g/10 min., and the blended polypropylene composition has a melt flow rate of greater than 5 g/10 min.
Abstract:
The present invention relates to elastic nonwoven materials comprising an elastic layer formed from a polymer blend comprising a propylene-based polymer and a minor amount of an ethylene-based polymer. The propylene-based polymer may comprise from about 75 to about 95 wt% propylene and from about 5 to about 25 wt% ethylene and/or a C 4 - Ci2 a-olefin, and may have a triad tacticity greater than about 90% and a heat of fusion less than about 75 J/g. The ethylene-based polymer may comprise from about 65 to about 100 wt% ethylene and from 0 to about 35 wt% of one or more C 3 -C 12 a-olefins.
Abstract:
Meltblown nonwoven compositions and processes for forming them are described herein. In one or more embodiments, the invention is directed to meltblown nonwoven fabrics having at least one elastic layer, wherein the elastic layer comprises a propylene-based polymer having an MFR greater than about 25 g/10 min. Additionally, the propylene-based polymer comprises from about 5 to about 25 wt% of one or more C2 and/or C4-Ci2 a-olefms and has a triad tacticity greater than about 90% and a heat of fusion less than about 75 J/g. The present invention is also directed to processes for forming meltblown nonwoven fabrics comprising forming a molten propylene-based polymer having an MFR of at least about 25 g/10 min, forming fibers comprising the propylene-based polymer, and forming an elastic nonwoven layer from the fibers.
Abstract:
Disclosed herein is a spunbond fiber of visbroken polypropylene having an Mw/Mn of from 3.5 to 7.0, an Mz/Mw of from greater than 2.0 and a melt flow rate (230/2.16) of from 50 to 100 dg/min. Also disclosed is a process for producing spunbond fibers comprising melt blending a polypropylene having a melt flow rate (230/2.16) of from 10 to 30 dg/min with a peroxide visbreaker such that the resulting melt flow rate of the visbroken polypropylene is from 50 to 100 dg/min; melt extruding the visbroken polypropylene through a die block such that filaments of the visbroken polypropylene being produced are exposed to a cabin pressure of from 4500 to 7000 Pa; and forming fibers of from less than 6.0 denier. Nonwoven fabrics and multiple-layer structures can be made from the fibers described herein that are useful for filtering and absorption related articles.
Abstract:
Provided is a propylene polymer composition comprising a neat polymer and a hydroxylamine ester compound suitable for preparing low melt viscosity polymers useful in spinning, melt blowing, extruding and the like. The polymer composition exhibits near-neat propylene polymer melt viscosity such that it can be readily pelletized for transport or use by an end user other than the composition manufacturer. Also provided are high quality non-woven fabrics and fabrics, particularly suitable for use as filter media, with superior filtration efficiencies and charge retention.
Abstract:
The present invention relates to bicomponent polymer fibers, and to processes for forming those fibers. Bicomponent polymer fibers are described, having a core comprising a core polymer and a sheath comprising a sheath polymer, wherein the sheath polymer is a polyolefm having an Mw less than about 65,000 g/mol. The core polymer has an Mw at least about 20,000 g/mol greater than the Mw of the sheath polymer. Processes for forming bicomponent fibers are also described, comprising (i) forming a molten blend of a core polymer and a sheath polymer; (ii) extruding the molten polymer blend using an extrusion die having a length to diameter ratio greater than or equal to about 10 and under shear conditions sufficient to drive the sheath polymer to the die wall; and (iii) forming meltblown fibers having a core comprising the core polymer and a sheath comprising the sheath polymer.
Abstract:
The present invention is directed to fabrics formed from the polymer blends. The polymer blends comprise from about 70 to about 99.9 wt%, based on the total weight of the composition, of a first propylene -based polymer and from about 0.1 to about 30 wt% of a second propylene based polymer. The first polymer has a melt flow rate of from about 100 to about 5,000 g/10 min, and the second polymer has a melt flow rate of from about 1 to about 500 g/min, and the second polymer has either a lower melt flow rate or a higher triad tacticity than the first polymer.
Abstract:
The present invention relates to bicomponent polymer fibers, and to processes for forming those fibers. Bicomponent polymer fibers are described, having a core comprising a core polymer and a sheath comprising a sheath polymer, wherein the sheath polymer is a polyolefm having an Mw less than about 65,000 g/mol. The core polymer has an Mw at least about 20,000 g/mol greater than the Mw of the sheath polymer. Processes for forming bicomponent fibers are also described, comprising (i) forming a molten blend of a core polymer and a sheath polymer; (ii) extruding the molten polymer blend using an extrusion die having a length to diameter ratio greater than or equal to about 10 and under shear conditions sufficient to drive the sheath polymer to the die wall; and (iii) forming meltblown fibers having a core comprising the core polymer and a sheath comprising the sheath polymer.