Fluoropolymer Hollow Fiber Membrane with Fluoro-copolymer and Fluoro -terpolymer bonded end portion(s)
A hollow fiber membrane fluid transport device is disclosed wherein the fibers are comprised of Polytetrafluoroethylene (PTFE), and the potting materials are comprised of fluorocopolymer and or fluoroterpolymer based materials. The potting of the device utilizes a compressed chemically resistant fluorocopolymer and or fluoroterpolymer film, allows for ease of manufacture without destruction of the PTFE hollow fibers, with high packing densities, and without the processing complexity of pre-melting, extruding, or chemical crosslinking of any polymeric adhesives. Furthermore, the PTFE hollow fibers can be treated with a fluoropolymeric solvent solution before the chemically resistant film is applied to enhance the adhesion of the PTFE fiber to the film. PTFE hollow fibers, and its respective fluoro-co and terpolymers as potting films impart high packing densities, superb chemical resistance and temperature resistance without membrane contamination, or low fiber pull strength, as is sometimes observed with standard potting materials such as polyurethane and epoxy.
1 . A fluid transport device comprised of the following:
a plurality of perfluorinated polymer fibers having an inner diameter, an outer diameter, two ends with a length between said ends, at least one end of each fiber open for fluid entrance or exit, said fibers arranged parallel one another and bonded over a length region by a segment of polymeric film, said segment of polymeric film contacting outer surface areas of the fibers in the region and filling interstitial volume between the fibers in said region.
2 . The device of claim 1 wherein the perfluorinated polymer fibers are polytetrafluoroethylene.
3 . The device of claim 1 wherein the fibers have a surface energy of less than about 20 dyne-cm.
4 . The device in claim 1 comprising a cylindrical containment shell, and contained within the shell are polytetrafluoroethylene hollow fibers that are bound together in bundles by at least one segment of film interwoven through the interstitial spaces between each of the fibers contacting each fiber near or at the ends of the bundles of the fibers.
5 . The device in claim 1 wherein the bundle of polytetrafluoroethylene hollow fibers that are bound together by at least one segment of film are heated above the melting point of the film at 80° C. to 300° C., and compressed, so that the melted film acts as a potting agent that binds the fibers resulting in densely packed fibers embedded in a solid mass, providing a fluid-tight seal around each fiber with the open ends of the fiber exposed on one or both sides of the potted end or ends.
6 . The device in claim 1 wherein the bundle of non-melting polytetrafluoroethylene hollow fibers that are bound together by at least one segment of film are heated above the melting point of the film at 80° C. to 300° C., and compressed, so that the melted film acts as the potting agent that binds the fibers resulting in densely packed fibers embedded in a solid mass, providing a fluid-tight seal around each fiber with the open ends of the fiber exposed on one or both sides of the potted end or ends.
7 . The device in claim 1 wherein the polytetrafluoroethylene hollow fibers are bound together in a densely packed fiber bundle by a fluoropolymer potting agent that binds the fibers on at least one end of the bundle in a solid mass, providing a fluid-tight seal around each fiber, and resulting in a potted bundle containing open ended fibers on the potted end or ends.
8 . The device of claim 4 wherein the cylindrical containment shell is comprised of polyvinylchloride, polysulfone, polyethersulfone, polycarbonate, polyether ether ketone, polyetherketone, polyamides, or polyimides.
9 . The device of claim 4 wherein said hollow fibers are comprised of fluorinated homopolymers such as polytetrafluoroethylene.
10 . The device of claim 4 wherein said potting film is selected from the group of materials comprising of perfluorinated copolymers of tetrafluoroethylene and hexafluoropropylene, copolymers of tetrafluoroethylene and alkoxy, copolymers of tetrafluoroethylene and perfluoropropylvinyl ether, copolymers of tetrafluoroethylene and chlorotrifluoroethylene, copolymers of ethylene such as ethylene and tetrafluoroethylene, or ethylene and fluorinated ethylene propylene, or similar fluorinated polymers such as DuPont™ SF-50 or Solvay™ Hyflon 940 AX.
11 . The device of claim 4 wherein said potting agent film is comprised of fluorinated terpolymers comprising of ethylene and vinylidene fluoride and hexafluoropropylene such as Dyneon™ THV.
12 . The device of claim 4 wherein the film is melted and compressed around the fibers.
13 . The device of claim 4 wherein the film around the fibers and the fiber bundle are compressed by a cylindrical metal band with overlapping edges bound by a constricting ring or rings that upon tightening results in the metal band to shrink in diameter.
14 . The device of claim 4 wherein the film around the fibers and the fiber bundle are compressed by a thermally activated shrinkable polymeric sleeve.
15 . The device of claim 4 wherein the film around the fibers and the fiber bundle are compressed by a cylindrical metal band with overlapping edges held by a collet that is tightened as the bundle is heated causing the metal band to reduce in diameter.
16 . The device of claim 4 wherein the film around the fibers and the fiber bundle are compressed by a cylindrical metal band that is expanded prior to application to the bundle after the placement of the film and then allowed to constrict in diameter with the use of a constricting band.
17 . The device of claim 4 which after melting and compressing the film around the fibers results in a packing density of greater than 65%.
18 . A composition containing polytetrafluoroethylene hollow fibers treated with a solution comprising a potting film or polymer used to prepare a potting film in solvents such as acetone, methyl ethyl ketone, ethyl acetate, butyl acetate, or N-methyl pyrrolidone.
19 . A hollow fiber membrane fluid transport device comprising a cylindrical containment shell, and contained within the shell is a bundle of polytetrafluoroethylene hollow fibers, wherein the bundle is formed by treating the fibers with a solvent polymer solution comprising a polymer used to prepare a potting film so that after the solvent is removed by drying, the fibers are bound together by at least one segment of film interwoven through interstitial spaces between the fibers and contacting the fibers near or at the ends.
20 . The hollow fiber membrane fluid transport device in claim 19 wherein the bundle of polytetrafluoroethylene hollow fibers treated with a solvent polymer solution are heated above the melting point of the film at 80° C. to 300° C., and compressed, so that the melted film acts as a potting agent that binds the fibers resulting in densely packed fibers embedded in a solid mass, providing a fluid-tight seal around each fiber with the open ends of each fiber exposed on one or both sides of the solid mass.
21 . The hollow fiber membrane fluid transport device of claim 19 wherein the polytetrafluoroethylene hollow fibers treated with a solvent polymer solution are bound together in a densely packed fiber bundle by the film used to bind the fibers on at least one end of the bundle in a solid mass, providing a fluid-tight seal around each fiber, and resulting in a potted bundle containing open ended fibers.
22 . The hollow fiber membrane fluid transport device of claim 19 wherein the cylindrical containment shell is comprised of polyvinylchloride, polysulfone, polyethersulfone, polycarbonate, polyether ether ketone, polyetherketone, polyamides, or polyimides.
23 . The hollow fiber membrane fluid transport device claim 19 wherein said hollow fibers are comprised of fluorinated homopolymers such as polytetrafluoroethylene.
24 . The hollow fiber membrane fluid transport device of claim 19 wherein said film is selected from the group of materials comprising perfluorinated copolymers of tetrafluoroethylene and hexafluoropropylene, copolymers of tetrafluoroethylene and alkoxy, copolymers of tetrafluoroethylene and perfluoropropylvinyl ether, copolymers of tetrafluoroethylene and chlorotrifluoroethylene, copolymers of ethylene such as ethylene and tetrafluoroethylene, or ethylene and fluorinated ethylene propylene, or similar fluorinated polymers such as DuPont™ SF-50 or Solvay™ Hyflon 940 AX.
25 . The hollow fiber membrane fluid transport device of claim 20 wherein the film comprises fluorinated terpolymers of ethylene and vinylidene fluoride and hexafluoropropylene such as Dyneon™ THV.
26 . The hollow fiber membrane fluid transport device of claim 19 wherein the solvent polymer solution comprises a terpolymer of tetrafluoroethylene and vinylidene fluoride and hexafluoropropylene and solvents such as acetone, methyl ethyl ketone, ethyl acetate, butyl acetate, or N-methyl pyrrolidone.
27 . The hollow fiber membrane fluid transport device of claim 19 wherein the solvent polymer solution comprises perfluorinated copolymers of tetrafluoroethylene and hexafluoropropylene, or tetrafluoroethylene and alkoxy, or tetrafluoroethylene and perfluoropropylvinyl ether, or tetrafluoroethylene and chlorotrifluoroethylene, or copolymers of ethylene such as ethylene and tetrafluoroethylene, ethylene and fluorinated ethylene propylene, or similar fluorinated polymers such as DuPont™ SF-50 or Solvay™ Hyflon 940 AX, and solvents such as acetone, methyl ethyl ketone, ethyl acetate, butyl acetate, or N-methyl pyrrolidone.
28 . The hollow fiber membrane fluid transport device of claim 19 wherein the device is formed by melting and compressing the film around the fibers.
29 . The hollow fiber membrane fluid transport device of claim 28 wherein the film around the fibers and the fiber bundle are compressed by a cylindrical metal band with overlapping edges bound by a constricting ring or rings.
30 . The hollow fiber membrane fluid transport device of claim 28 wherein the film around the fibers and the fiber bundle are compressed by a thermally activated shrinkable polymeric sleeve.
31 . The hollow fiber membrane fluid transport device of claim 28 wherein the film around the fibers and the fiber bundle are compressed by a cylindrical metal band with overlapping edges held by a collet that is tightened as the bundle is heated causing the metal band to reduce in diameter.
32 . The hollow fiber membrane fluid transport device of claim 28 wherein the film around the fibers and the fiber bundle are compressed by a cylindrical metal band that is expanded prior to application to the bundle after placement of the film and then allowed to constrict in diameter with the use of a constricting band.
33 . The hollow fiber membrane fluid transport device of claim 28 which after melting and compressing the film around the fibers results in a packing density of greater than 65%.