Multi-zone spinneret, apparatus and method for making filaments and nonwoven fabrics therefrom
A spinneret, apparatus, and method are provided for making filaments for fibrous nonwoven fabrics with more uniform filament and fabric formation while minimizing filament breaks and hard spot defects in webs and fabrics made therefrom. The spinneret has a spinneret body that has an overall length to hydraulic diameter ratio and defines orifices that extend through the spinneret body, wherein the orifices comprise capillaries that open at a face of the spinneret body for polymer filament extrusion therefrom, wherein the capillaries are arranged in a plurality of different rows at the face of the spinneret body, and wherein the plurality of different rows are arranged into a plurality of different zones at the face of the spinneret body. A spinneret body of the spinneret can have an overall length to hydraulic ratio of at least 3 percent and/or a zone-to-zone length to hydraulic ratio of at least 2% and/or the hydraulic diameters, lengths, and length to hydraulic diameter ratios can progressively increase or decrease zone-to-zone for at least three different zones of capillaries, which can be applied to cross-flow quench or quench from a single-side. The spinneret body is designed to better accommodate differing operational proximity of the various different zones to quench air sources or source at commercially useful throughputs and fiber uniformity.
1. A process for melt-spinning polymeric filaments, comprising:
extruding molten polymer through a spinneret to produce a plurality of extruded filaments below the spinneret;
passing the plurality of extruded filaments through a quench region below the spinneret, wherein said extruded filaments are quenched by directing at least one stream of cooling gas beneath the spinneret and across the extruded filaments to provide a plurality of quenched filaments; and
collecting the plurality of quenched filaments,
wherein the spinneret comprises:
a spinneret body having a non-circular periphery and is configured to provide a uniform filament denier, the spinneret body has an overall length to hydraulic diameter ratio and defining orifices extending through the spinneret body, wherein the orifices comprise capillaries that open at a face of the spinneret body for polymer filament extrusion therefrom, wherein the capillaries are arranged in a plurality of different rows at the face of the spinneret body, and wherein the plurality of different rows are arranged into a plurality of different zones at the face of the spinneret body, wherein the plurality of different zones includes:
(i) a first zone located centrally at the face of the spinneret body, comprising a plurality of first rows, each of said first rows comprising a plurality of first capillaries, wherein the first capillaries are arranged in a first capillary density, and the first capillaries individually having a first cross-sectional shape, a first hydraulic diameter, a first length, and a first length to hydraulic diameter ratio,
(ii) a second zone located adjacent to the first zone at the face of the spinneret body, comprising a plurality of second rows, each of said second rows comprising a plurality of second capillaries, wherein the second capillaries are arranged in a second capillary density, and the second capillaries individually having a second cross-sectional shape, a second hydraulic diameter, a second length, and a second length to hydraulic diameter ratio, and
(iii) a third zone located adjacent to the first zone at the face of the spinneret body, comprising a plurality of third rows, each of said third rows comprising a plurality of third capillaries, wherein the third capillaries are arranged in a third capillary density and the third capillaries individually having a third cross-sectional shape, a third hydraulic diameter, a third length, and a third length to hydraulic diameter ratio;
wherein the first zone is located between the second and third zones, and the first zone is closer to a center of the face of the spinneret body than the second and third zones, and wherein the overall length to hydraulic diameter ratio is at least 3 percent;
and wherein the first hydraulic diameter of each of the first capillaries is less than the second hydraulic diameter of each of the second capillaries, and the first hydraulic diameter of each of the first capillaries is less than the third hydraulic diameter of each of the third capillaries.
2. The process of claim 1 , wherein the first length of each of the first capillaries is less than the second length of each of the second capillaries, and the first length of each of the first capillaries is less than the third length of each of the third capillaries.
3. The process of claim 1 , wherein the first cross-sectional shape of each of the first capillaries and the second cross-sectional shape of each of the second capillaries and the third cross-sectional shape of each of the third capillaries are the same.
4. The process of claim 3 , wherein the first cross-sectional shape of each of the first capillaries and the second cross-sectional shape of each of the second capillaries and the third cross-sectional shape of each of the third capillaries are circular or oval.
5. The process of claim 1 , wherein the first length to hydraulic diameter ratio of each of the first capillaries is less than the second length to hydraulic diameter ratio of each of the second capillaries, and the first length to hydraulic diameter ratio of each of the first capillaries is less than the third length to hydraulic diameter ratio of each of the third capillaries.
6. The process of claim 5 , wherein the second length to hydraulic diameter ratio of each of the second capillaries and the third length to hydraulic diameter ratio of each of the third capillaries are the same.
7. The process of claim 1 , wherein the first capillary density is greater than each of the second capillary density and the third capillary density.
8. The process of claim 1 , wherein the step of passing the plurality of extruded filaments through a quench region below the spinneret comprises quenching said plurality of extruded filaments by directing the at least one stream of cooling gas in one or more cross-flowing directions beneath the spinneret and across the plurality of extruded filaments.
9. The process of claim 1 , wherein the spinneret further comprises:
a fourth zone comprising a plurality of fourth rows, each of said fourth rows comprising a plurality of fourth capillaries, wherein the fourth capillaries are arranged in a fourth capillary density, and the fourth capillaries individually having a fourth cross-sectional shape, a fourth hydraulic diameter, a fourth length, and a fourth length to hydraulic diameter ratio, and
a fifth zone comprising a plurality of fifth rows, each of said fifth rows comprising a plurality of fifth capillaries, wherein the fifth capillaries are arranged in a fifth capillary density and the fifth capillaries individually having a fifth cross-sectional shape, a fifth hydraulic diameter, a fifth length, and a fifth length to hydraulic diameter ratio;
wherein the first zone is located between the fourth and fifth zones, and
wherein the fourth hydraulic diameter of each of the fourth capillaries and the fifth hydraulic diameter of each of the fifth capillaries are less than the second hydraulic diameter of each of the second capillaries and are less than the third hydraulic diameter of each of the third capillaries; and the first hydraulic diameter of each of the first capillaries is less than the fourth hydraulic diameter of each of the fourth capillaries, and the first hydraulic diameter of each of the first capillaries is less than the fifth hydraulic diameter of each of the fifth capillaries; and
wherein the fourth length of each of the fourth capillaries and the fifth length of each of the fifth capillaries are less than the second length of each of the second capillaries and the third length of each of the third capillaries; and the first length of each of the first capillaries is less than the fourth length of each of the fourth capillaries, and the first length of each of the first capillaries is less than the fifth length of each of the fifth capillaries.
10. The process of claim 9 , wherein the first capillary density, the fourth capillary density, and the fifth capillary density are the same.
11. The process of claim 9 , wherein the first length to hydraulic diameter ratio of each of the first capillaries is less than the fourth length to hydraulic diameter ratio of each of the fourth capillaries, and the first length to hydraulic diameter ratio of each of the first capillaries is less than the fifth length to hydraulic diameter ratio of each of the fifth capillaries.
12. The process of claim 1 , wherein the spinneret body has a plurality of zone-to-zone length to hydraulic diameter ratios, and wherein at least one of said zone-to-zone length to hydraulic diameter ratios is 2% or greater.
13. The process of claim 1 , wherein the spinneret body has an overall length to hydraulic diameter ratio of at least 5%.
14. The process of claim 1 , wherein a sum of the capillaries that open at the face of the spinneret body is at least 3000.
15. The process of claim 1 , wherein the face of the spinneret body is polygonal.
16. The process of claim 1 , wherein the face of the spinneret body is rectangular.
17. A process for melt-spinning polymeric filaments, comprising:
extruding molten polymer through a spinneret to produce a plurality of extruded filaments below the spinneret;
passing plurality of extruded filaments through a quench region below the spinneret, wherein said filaments are quenched by directing at least one stream of cooling gas in one direction free of opposite flowing cooling gas beneath the spinneret and across the plurality of extruded filaments to provide a plurality of quenched filaments; and
collecting the plurality of quenched filaments,
wherein the spinneret comprises:
a spinneret body having a non-circular periphery and is configured to provide a uniform filament denier, that spinneret body has an overall length to hydraulic diameter ratio and defining orifices extending through the spinneret body, wherein the orifices comprise capillaries that open at a face of the spinneret body for polymer filament extrusion therefrom, wherein the capillaries are arranged in a plurality of different rows at the face of the spinneret body, and wherein the plurality of different rows are arranged into a plurality of different zones at the face of the spinneret body, wherein the plurality of different zones comprises:
(i) a first zone located centrally at the face of the spinneret body, comprising a plurality of first rows, each of said first rows comprising a plurality of first capillaries, wherein the first capillaries are arranged in a first capillary density, and the first capillaries individually having a first cross-sectional shape, a first hydraulic diameter, a first length, and a first length to hydraulic diameter ratio,
(ii) a second zone located adjacent to the first zone at the face of the spinneret body, comprising a plurality of second rows, each of said second rows comprising a plurality of second capillaries, wherein the second capillaries are arranged in a second capillary density, and the second capillaries individually having a second hydraulic diameter, a second cross-sectional shape, a second length, and a second length to hydraulic diameter ratio, and
(iii) a third zone located adjacent to the first zone at the face of the spinneret body, comprising a plurality of third rows, each of said third rows comprising a plurality of third capillaries, wherein the third capillaries are arranged in a third capillary density and the third capillaries individually having a third cross-sectional shape, a third hydraulic diameter, a third length, and a third length to hydraulic diameter ratio,
wherein the first zone is located between the second and third zones,
wherein the third hydraulic diameter of each of the third capillaries is less than the first hydraulic diameter of each of the first capillaries, and the first hydraulic diameter of each of the first capillaries is less than the second hydraulic diameter of each of the second capillaries,
wherein the third length of each of the third capillaries is less than the first length of each of the first capillaries, and the first length of each of the first capillaries is less than the second length of each of the second capillaries, and
wherein the third length to hydraulic diameter ratio of each of the third capillaries is less than the first length to hydraulic diameter ratio of each of the first capillaries, and the first length to hydraulic diameter ratio of each of the first capillaries is less than the second length to hydraulic diameter ratio of each of the second capillaries.
18. The process of claim 17 , wherein the spinneret body has a plurality of zone-to-zone length to hydraulic diameter ratios, and wherein at least one of said zone-to-zone length to hydraulic diameter ratios is at least 2%.
19. The process of claim 17 , wherein the first capillary density, the second capillary density, and the third capillary density are the same.