Classifications

• • D—TEXTILES; PAPER
  • D01—NATURAL OR MAN-MADE THREADS OR FIBRES; SPINNING
  • D01F—CHEMICAL FEATURES IN THE MANUFACTURE OF ARTIFICIAL FILAMENTS, THREADS, FIBRES, BRISTLES OR RIBBONS; APPARATUS SPECIALLY ADAPTED FOR THE MANUFACTURE OF CARBON FILAMENTS
  • D01F1/00—General methods for the manufacture of artificial filaments or the like
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B05—SPRAYING OR ATOMISING IN GENERAL; APPLYING FLUENT MATERIALS TO SURFACES, IN GENERAL
  • B05B—SPRAYING APPARATUS; ATOMISING APPARATUS; NOZZLES
  • B05B9/00—Spraying apparatus for discharge of liquids or other fluent material, without essentially mixing with gas or vapour
  • B05B9/03—Spraying apparatus for discharge of liquids or other fluent material, without essentially mixing with gas or vapour characterised by means for supplying liquid or other fluent material
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B05—SPRAYING OR ATOMISING IN GENERAL; APPLYING FLUENT MATERIALS TO SURFACES, IN GENERAL
  • B05B—SPRAYING APPARATUS; ATOMISING APPARATUS; NOZZLES
  • B05B15/00—Details of spraying plant or spraying apparatus not otherwise provided for; Accessories
  • B05B15/20—Arrangements for agitating the material to be sprayed, e.g. for stirring, mixing or homogenising
  • B05B15/25—Arrangements for agitating the material to be sprayed, e.g. for stirring, mixing or homogenising using moving elements, e.g. rotating blades
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B05—SPRAYING OR ATOMISING IN GENERAL; APPLYING FLUENT MATERIALS TO SURFACES, IN GENERAL
  • B05B—SPRAYING APPARATUS; ATOMISING APPARATUS; NOZZLES
  • B05B7/00—Spraying apparatus for discharge of liquids or other fluent materials from two or more sources, e.g. of liquid and air, of powder and gas
  • B05B7/14—Spraying apparatus for discharge of liquids or other fluent materials from two or more sources, e.g. of liquid and air, of powder and gas designed for spraying particulate materials
  • B05B7/1404—Arrangements for supplying particulate material
  • B05B7/1409—Arrangements for supplying particulate material specially adapted for short fibres or chips

Definitions

• Nanofibers are generally defined as fibers having a diameter of less than about 1000 nm in diameter and may have lengths from a few centimeters to less than one millimeter . Such fibers have come into use in various fields, including medical applications, protective materials, general textiles and filtration media.
• a liquid such as a polymer
• a stream of hot gas such as air.
• Thread or fibers are formed which are dried and collected on a collector by use of a vacuum applied through the collector.
• such a method has lower energy requirements than known systems, requiring less heat input to form such nanofibers.
• such a system and method produce nanofibers on a commercial scale that is less capital intensive than known systems and produces a higher output as well as a higher throughput than known systems.
• FIG. 1 is a schematic illustration of an exemplary system for the manufacture of nanofibers.
• FIG. 1 there is shown a schematic illustration of an exemplary system 10 for the application of nano fibers N onto a substrate S.
• the system 10 includes a feed tank 12 for storing a fluid, such as a liquid polymeric feed solution F, an outlet pump 14, fluid conduits 16, such as piping, hoses or the like, and an applicator head 18.
• a control system or controller 20 monitors and controls the overall operation of the system 10.
• a conveyor 22 can be used to move the substrate S along a path P relative to the applicator system 10 and head 18.
• the tank 12 can be formed of any material suitable and/or compatible with the feed solution F. Such materials include, but are not limited to stainless steel, polypropylene or the like.
• the system 10 is configured to apply the nanofiber N solution to a substrate S.
• the nanofiber N can be applied to, for example, a coarse web, a fine web, a non- woven material or essentially any type or construction of suitable substrate.
• An agitator 24 is positioned in the tank 12 to maintain the nano fibers in solution.
• One agitator 24 is a multi-blade rotary agitator, preferably powered by a variable speed drive 28.
• a variable speed drive 28 allows for controlling the consistency of the solution- that is maintaining the nanofiber evenly distributed and suspended in the solution, while minimizing over-working or over-agitating the solution and controlling the power consumption of the agitator 24.
• agitators that can be used to maintain the nanofibers in solution.
• the outlet pump 14 provides a metered or precise fluid flow to the applicator head 18.
• One type of pump 14 is a metering pump (or multiple metering pumps) to provide precise flow to the applicator head 18.
• the fluid conduits 16 extending between the tank 12 and the pump 14 and the pump 14 and the applicator head 18 are configured to maintain the fiber in solution and to prevent the nanofibers from falling out of solution or settling in the piping or hoses 16.
• the piping or hoses 16 between the various system components can be designed having straight runs to reduce or eliminate bends, or where necessary an increased the radius of curvature of bends.
• Conduits 16 having smooth internal surfaces to minimize flow resistance and interferences, cavities (or flow dead spots) and the like, can be used maintain a desired flow rate and /or velocity through the conduits 16.
• One or more flow meters 30 properly positioned within the system 10 provide for monitoring the inlet of carrier fluid C (e.g., water) to the tank 12 and the flow of the nanofibers in solution N from the tank 12.
• carrier fluid C e.g., water
• the materials of the conduits 16 and other process equipment are selected to be suitable and/or compatible with the nanofiber formulation.
• the applicator head 18 is configured as a building block-type expandable design in which sections can be added or removed depending on the width of the substrate S.
• the applicator head 18 sections can be made up of a variety of nozzle designs depending on the specific formulation and the intended coat weight of nanofibers on the substrate S.
• the applicator head 18 can atomize the formulation through pressure generated from the pump 14 at the outlet side of the tank 12. Exemplary of such applicators are those described in Budai, U.S. Patent Application Serial No. 13/547,685, which application is commonly assigned with the present application and is incorporated herein by reference in its entirety.
• the system 10 is controlled by the controller 20.
• the controller 20 can, for example, monitor the line speed of the substrate S and vary the nanofiber formulation output flow based on the line speed of the substrate S, the density at which the nanofiber formulation is applied to substrate S (coating weight), the pump 14 outputs and inputs, and like process parameters.
• the controller 20 can also monitor and control the agitator 24, process temperatures and the like. It is anticipated that the controller 20 will be of a menu driven type.
• the present system 10 is configured to apply nanofiber to a wide variety of substrates S.
• Exemplary nanofiber is that formulated from cellulose acetate, polypropylene, polyethylene, polyester, nylon, polyphthalamide (PPA), polymethyl methacrylate (PMMA), polyactic acid, poly aniline, poly vinyl alcohol, poly acrylonitrile and the like.
• PPA polyphthalamide
• PMMA polymethyl methacrylate
• polyactic acid poly aniline
• poly vinyl alcohol poly vinyl alcohol
• poly acrylonitrile polyacrylonitrile
• suitable polymers will be appreciated by those skilled in the art.
• the polymer can be carried in a wide variety of suitable liquid carriers C, such as water.
• Other additives may be used to create a desired viscosity or nanofiber suspension, including for example, surfactants such as glycerin.
• a method of applying nanofibers to a substrate S includes providing a substrate and a system 10 for applying the nano fiber solution to the substrate and moving the substrate S and system 10 relative to one another. It is anticipated that the substrate S will move relative to the applicator head 18. The method further includes conveying, from a storage vessel such as a tank 12, a liquid formulation of nanofibers N in suspension, through one or more fluid conduits 16, to the applicator head 18.
• a storage vessel such as a tank 12
• a liquid formulation of nanofibers N in suspension through one or more fluid conduits 16, to the applicator head 18.
• the fluid flow is carefully controlled and monitored. As such the flow can be measured, as by one or more flow meters 30 or like device, at the tank 12 outlet (e.g., the pumped fluid) and the flow rate monitored to ensure that a desired flow rate is maintained. To assure that the formulation in the tank 12 is maintained (e.g., the concentration of nanofibers in the solution), the carrier C inlet to the tank 12 can also be monitored.
• the formulation in the tank 12 e.g., the concentration of nanofibers in the solution
• the carrier C inlet to the tank 12 can also be monitored.
• the liquid formulation of nanofibers in suspension is transported through a system that reduces the number of bends or other interferences in flow.
• the method further includes applying the formulation to a substrate through an applicator head 18 such as that described above.
• the nanofiber formulation will be applied at a predetermined coat weight and may depend upon the specific formulation used and the intended use of the resultant coated substrate. It is anticipated that the formulation may be applied by spray, atomization (effected by pump pressure) or like methods.
• the present system 10 and method can greatly reduce the energy requirements for applying nanofibers N to substrates S. It is expected that the overall cost of nanofiber production can be reduced by as much as fifty percent with production yields being twenty times greater than known methods such as electrospinning.
• the present process can be carried out at or about room temperature, thus greatly reducing the energy costs over known systems and methods.
• functional composites can be made by selectively incorporating materials such as silica, clay, silver particles, titanium and aluminum-based materials and the like.
• nanofibers can be produced for use in the medical, energy, filtration and lighting industries, as well as for use in general textiles.

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• Engineering & Computer Science (AREA)
• Manufacturing & Machinery (AREA)
• Chemical & Material Sciences (AREA)
• Chemical Kinetics & Catalysis (AREA)
• General Chemical & Material Sciences (AREA)
• Textile Engineering (AREA)
• Nonwoven Fabrics (AREA)
• Spinning Methods And Devices For Manufacturing Artificial Fibers (AREA)
• Application Of Or Painting With Fluid Materials (AREA)
• Nozzles (AREA)
• Spray Control Apparatus (AREA)

Applications Claiming Priority (3)

Publications (1)

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• 2013
  • 2013-08-16 US US13/968,736 patent/US20140134346A1/en not_active Abandoned
  • 2013-10-25 JP JP2015541799A patent/JP2016504177A/ja active Pending
  • 2013-10-25 WO PCT/US2013/066851 patent/WO2014074328A1/en active Application Filing
  • 2013-10-25 EP EP13788854.1A patent/EP2916966A1/en not_active Withdrawn

Non-Patent Citations (2)

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