Zoned spinneret and nonwoven fabrics

Abstract

A spinneret for melt-spinning polymeric fibers including a spinneret body defining a plurality of orifices extending through the spinneret body, wherein the plurality of orifices each comprise a capillary that open at a face of the spinneret body for polymer filament extrusion therefrom. The plurality of orifices include (i) a first group of orifices each having a first capillary having a first capillary length (L) and first capillary hydraulic diameter (DH) defining a first L/DH ratio; and (ii) a second group of orifices each having a second capillary having a second capillary length (L) and second capillary hydraulic diameter (DH) defining a second L/DH ratio, in which the first L/DH ratio is larger than the second L/DH ratio. The first group of orifices define at least one first zone at the face of the spinneret body, and the second group of orifices define at least one second zone at the face of the spinneret body.

1 . A spinneret for melt-spinning polymeric fibers, comprising:
 a spinneret body defining a plurality of orifices extending through the spinneret body, wherein the plurality of orifices each comprise a capillary that open at a face of the spinneret body for polymer filament extrusion therefrom;   wherein the plurality of orifices include at least two (2) or more groups of orifices in which each group of orifices has a different respective capillary length (L) and a different respective capillary hydraulic diameter (D H ) defining a respective L/D H  ratio including (i) a first group of orifices each having a first capillary having a first capillary length (L) and first capillary hydraulic diameter (D H ) defining a first L/D H  ratio; and (ii) a second group of orifices each having a second capillary having a second capillary length (L) and second capillary hydraulic diameter (D H ) defining a second L/D H  ratio, the first L/D H  ratio is larger than the second L/D H  ratio;   wherein the first group of orifices define at least one first zone at the face of the spinneret body, and the second group of orifices define at least one second zone at the face of the spinneret body.   
     
     
         2 . The spinneret of  claim 1 , wherein the first L/D H  ratio is from about 0.9 to about 10, and the second L/D H  ratio is from about 0.8 to about 9. 
     
     
         3 . The spinneret of  claim 1 , wherein the spinneret body includes a zoned-ratio between the first L/D H  ratio and the second L/D H  ratio from about 1.1:1 to about 12.5:1. 
     
     
         4 . The spinneret of  claim 1 , wherein the plurality of orifices comprises from about 50 to about 95% by number of the first group of orifices and comprises from about 5 to about 50% by number of the second group of orifices. 
     
     
         5 . The spinneret of  claim 1 , wherein the first capillaries of the first group of orifices have a first ribbon cross-section at the face of the spinneret body, wherein the first ribbon cross-section has an aspect ratio from about 1.5:1 to about 10:1. 
     
     
         6 . The spinneret of  claim 1 , wherein the second capillaries of the second group of orifices have a second ribbon cross-section at the face of the spinneret body, wherein the first ribbon cross-section has an aspect ratio from about 1.5:1 to about 10:1. 
     
     
         7 . The spinneret of  claim 1 , wherein the first capillaries of the first group of orifices have a first round cross-section at the face of the spinneret body, wherein the first round cross-section has an aspect ratio from 0.8:1 to 1.2:1. 
     
     
         8 . The spinneret of  claim 1 , wherein the second capillaries of the second group of orifices have a second round cross-section at the face of the spinneret body, wherein the second round cross-section has an aspect ratio from 0.8:1 to 1.2:1. 
     
     
         9 . The spinneret of  claim 1 , wherein the at least one second zone comprises a first group of one or more rows including a first outermost row extending along a width direction of the spinneret body. 
     
     
         10 . The spinneret of  claim 9 , wherein the at least one second zone comprises a second group of one or more rows including a second outermost row extending along the width direction of the spinneret body. 
     
     
         11 . The spinneret of  claim 10 , wherein the at least one first zone comprises a third group of one or more rows extending along a width direction of the spinneret body and being located directly or indirectly between the first group of one or more rows and the second group of one or more rows. 
     
     
         12 . The spinneret of  claim 1 , wherein the at least one first zone comprises a plurality of first zones, and the at least one second zone comprises a plurality of second zones, wherein the plurality of first zones and the plurality of second zones are located in an alternating pattern along (a) a length direction, (b) a width direction, or (c) both (a) and (b). 
     
     
         13 . The spinneret of  claim 1 , wherein (a) the at least one first zone comprises a continuous sea of the plurality of orifices, and the at least one second zone comprises a plurality of second zones comprising islands of the plurality of orifices dispersed throughout the continuous sea of the plurality of orifices, or (b) the at least one second zone comprises a continuous sea of the plurality of orifices, and the at least one first zone comprises a plurality of first zones comprising islands of the plurality of orifices dispersed throughout the continuous sea of the plurality of orifices. 
     
     
         14 . A die, comprising:
 (i) a spinneret according to  claim 1 ; and   (ii) a polymer distribution pathway operatively connecting a first inlet to each of the plurality of orifices of the spinneret;   
     
     
         15 . A system, comprising:
 (i) a die according to  claim 14 ;   (ii) a polymer source comprising a polymeric composition, wherein the polymer source is operatively connected to the first inlet of the die.   
     
     
         16 . A nonwoven fabric, comprising:
 a plurality of interlaid fibers comprising a plurality of monocomponent fibers, wherein the plurality of monocomponent fibers include (i) a first group of monocomponent fibers the first group of monocomponent fibers having a first onset of melting temperature and (ii) a second group of monocomponent fibers defining at least one second region, the second group of monocomponent fibers having a second onset of melting temperature, wherein the second onset of melting temperature is lower than the first onset of melting temperature;   wherein the plurality of monocomponent fibers are formed from a single polymeric composition.   
     
     
         17 . The nonwoven fabric of  claim 16 , wherein the nonwoven fabric is consolidated via the second group of monocomponent fibers, wherein the second group of monocomponent fibers are deformed from an initially spun cross-section and fused with the second group of monocomponent fibers. 
     
     
         18 . A composite, comprising a nonwoven fabric according to  claim 16 , and a film layer bonded to the nonwoven fabric. 
     
     
         19 . A method of producing a nonwoven fabric, comprising:
 (i) simultaneously melt spinning a plurality of monocomponent fibers from a single polymeric composition via a single spinneret, the plurality of monocomponent fibers comprising a first group of monocomponent fibers having a first onset of melting temperature and a second group of monocomponent fibers having a second onset of melting temperature, wherein the second onset of melting temperature is lower than the first onset of melting temperature, and   wherein the plurality of monocomponent fibers form at least one first region including at least a majority by number of fibers of a portion of the first group of monocomponent fibers and at least one second region including at least a majority by number of fibers of a portion of the second group of monocomponent fibers;   (ii) collecting the plurality of monocomponent fibers; and   (iii) consolidating the plurality of monocomponent fibers.   
     
     
         20 . The method of  claim 19 , wherein consolidating the plurality of monocomponent fibers comprises bonding the plurality of monocomponent fibers via a through-air-bonding (TAB) process comprising subjecting the plurality of monocomponent fibers to an elevated temperature equal to or greater than the second onset of melting temperature but below the first onset of melting temperature.