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US 10,041,188 B2Granted
Method and apparatus for production of meltblown nanofibers
AssigneeHills, Inc.
InventorsJames E. Brang, Arnold Wilkie, Jeff Scott Haggard
Life of this patent
Estimating the term…
Abstract
An apparatus for producing polymeric nanofibers utilizes a meltblown spinneret die having spin holes formed by grooves in plate(s) surface(s) of plate(s) where polymer exits at the plate(s) edge(s). The grooves are smaller than 0.005″ wide×0.004″ deep and have an L/D at least as large as 20:1. Flow rates of polymer through the apparatus are very low, on the order of 0.01 ghm or less. A meltblown fabric having fibers mostly less than 0.5 microns in diameter is produced.
Claims27
A nanofiber meltblown fiber spinning device into which molten polymer is fed comprising:
- at least a first flow distribution plate having an outflow edge and a pattern of flow regions defined therein, said pattern of flow regions comprising a reservoir portion for receiving polymer fed to the device and a plurality of spinning orifices defined as respective long, narrow, parallel flow passages, said spinning orifices being positioned in flow communication with said reservoir and extending to said outflow edge such that nanofibers of said polymer are extruded from said spinning orifices, said plate having a plate thickness defined between first and second opposite plate surfaces, wherein said flow regions are grooves that include said spinning orifices and are recessed in said first surface to a depth less than said thickness;
- wherein said spinning orifices are long and narrow spin holes having a length L and a maximum transverse dimension D and the ratio L/D is equal to or greater than twenty;
- and
- wherein said spinning device is configured to form said nanofibers such that when polymer flows through said spinning orifices at low flow rates of 0.01 grams per spinning orifice per minute or less a majority of the formed fibers have a diameter less than 0.5 micron.
1 more element
A nanofiber meltblown fiber spinning device into which molten polymer is fed comprising:
- at least a first flow distribution plate having an outflow edge and a pattern of flow regions defined therein, said pattern of flow regions comprising a reservoir portion for receiving polymer fed to the device, and a plurality of spinning orifices defined as respective long, narrow, parallel flow passages, said spinning orifices being positioned in flow communication with said reservoir and extending to said outflow edge such that nanofibers of said polymer are extruded from said spinning orifices, said plate having a plate thickness defined between first and second opposite plate surfaces, wherein said flow regions are grooves that include said spinning orifices and are recessed in said first surface to a depth less than said thickness;
- wherein said spinning device is configured to form fibers such that a majority of the formed fibers have a diameter less than 0.5 micron, wherein said spinning orifices are long and narrow spin holes having a length L and a maximum cross-section dimension D no greater than 0.005 inch wide and are arranged in a substantially linear array having a density greater than one hundred holes per inch, and wherein the ratio L/D is equal to or greater than one hundred.
A nanofiber meltblown fiber spinning device into which molten polymer is fed comprising:
- at least a first flow distribution plate having an outflow edge and a pattern of flow regions defined therein, said pattern of flow regions comprising a reservoir portion for receiving polymer fed to the device and a plurality of spinning orifices defined as respective long, narrow, parallel flow passages, said spinning orifices being positioned in flow communication with said reservoir and extending to said outflow edge such that nanofibers of said polymer are extruded from said spinning orifices, wherein said plate has a plate thickness defined between first and second opposite plate surfaces, and said flow regions comprise grooves that define at least a portion of said spinning orifices and that are recessed in said first surface to a depth less than said thickness;
- and
- a pump unit for feeding said polymer from at least one source to said device;
- wherein said spinning device is configured to form fibers such that when polymer flows through said spinning orifices at a low flow rate of 0.01 grams per spinning orifice per minute or less a majority of the formed fibers have a diameter less than 0.5 micron, said spinning orifices being long narrow spin holes having a length L and a maximum transverse dimension D and the ratio L/D is equal to or greater than twenty, said spinning orifices having a cross-section no greater than 0.005 inch wide and, in order to compensate for low productivity per spinning orifice resulting from said low flow rate, the spinning orifices are arranged at said outflow edge in a substantially linear array having a density greater than one hundred orifices per inch, and
- wherein said spinning device and said pump unit are configured to facilitate feeding of said molten polymer from said at least one source to said reservoir portion at said low flow rate or less.
2 more elements
A nanofiber meltblown fiber spinning device into which molten polymer is fed comprising:
- at least a first flow distribution plate having an outflow edge and a pattern of flow regions defined therein, said pattern of flow regions comprising a reservoir portion for receiving polymer fed to the device and a plurality of spinning orifices defined as respective long, narrow, parallel flow passages, said spinning orifices being positioned in flow communication with said reservoir and extending to said outflow edge such that nanofibers of said polymer are extruded from said spinning orifices, said plate having a plate thickness defined between first and second opposite plate surfaces, wherein said flow regions are grooves that include said spinning orifices and are recessed in said first surface to a depth less than said plate thickness;
- wherein said spinning orifices are long and narrow spin holes having a cross-section no greater than 0.005 inch wide and are arranged in a substantially linear array having a density greater than one hundred holes per inch;
- and
- wherein said spinning orifices have a length L and a maximum transverse dimension D, and the ratio L/D is equal to or greater than one hundred.
1 more element
A nanofiber meltblown fiber spinning device into which molten polymer is fed from a polymer source to said device, said device comprising:
- a first flow distribution plate having a first surface and an outflow edge and wherein multiple parallel spinning orifices are defined in said surface and terminate in a linear array at said outflow edge;
- wherein said spinning orifices are long and narrow with a length L and a maximum transverse dimension D such that the ratio L/D is greater than twenty;
- wherein said spinning orifices are configured such that when polymer from said polymer source flows through said spinning orifices at a low flow rate of 0.01 grams per spinning orifice per minute or less a majority of fibers flowing out from said spinning orifice at said outflow edge have a diameter less than 0.5 micron;
- and
- wherein said long and narrow spinning orifices in said linear array are arranged in a high density greater than one hundred spinning orifices per inch to compensate for low productivity per spinning orifice resulting from said low flow rate.
2 more elements
A nanofiber meltblown fiber spinning device into which molten polymer is fed from polymer supply means to said device, said device comprising:
- a first flow distribution plate having a first surface and an outflow edge and wherein multiple parallel spinning orifices are defined in said surface and terminate in a linear array at said outflow edge;
- and
- wherein said spinning orifices are long and narrow with a length L and a maximum transverse dimension D such that the ratio L/D is greater than twenty and D is no greater than 0.005 inch.
Dependencies are inferred from the claim text.