Abstract:
The present invention relates to a medical device and method of forming the medical device. In particular, the present invention relates to a medical device having a tubular membrane structure over a radially expandable structural frame, and to a method of forming the tubular membrane on the radially expandable structural frame. In one aspect, a structural frame is placed over a spinning mandrel and a fiber is electro-statically spun over at least a portion of the structural frame forming a membrane. A transfer sheath may be used between the mandrel and structural frame to prevent the electro-statically spun fiber from adhering to the mandrel. In another aspect, a first membrane is spun over the mandrel before the structural frame is placed over the mandrel. In this aspect, at least a portion of the structural frame is sandwiched between the membranes. The membrane or membranes and structural frame form a fiber spun frame assembly. The fiber spun frame assembly may be coated with an elastic polymer. In addition, the membrane or membranes may go through some post processing to achieve desired characteristics or configurations.
Abstract:
High flux porous hollow fiber membranes are produced from perfluorinated thermoplastic polymers by extruding a heated solution of the polymer having a lower critical solution temperature directly into a cooling bath to form the porous membrane by liquid-liquid phase separation. Extrusion can be conducted either vertically or horizontally.
Abstract:
The processes and apparatus of the present invention concern melt spinning high viscosity fluoropolymers into single filaments or multi-filament yarns at high spinning speeds.
Abstract:
High flux porous hollow fiber membranes are produced from perfluorinated thermoplastic polymers by extruding a heated solution of the polymer having a lower critical solution temperature directly into a cooling bath to form the porous membrane by liquid-liquid phase separation. Extrusion can be conducted either vertically or horizontally.
Abstract:
A process for producing plexifilamentary products by spinning from a spin fluid of a polyolefin dissolved in a primary spin agent selected from the group consisting of 1,1,2-trichloro-2,2-difluoroethane and isomers thereof; 1,1,3-trichloro-2,2,3,3-tetrafluoropropane and isomers thereof; 1,2-dichloro-3,3,3-trifluoropropane and isomers thereof; and 1,2-dichloro-1-fluoroethylene; and a co-spin agent; and also a spin fluid of a polyolefin dissolved in a primary spin agent selected from the group consisting of 1,1,2-trichloro-2,2-difluoroethane and isomers thereof; 1,1,3-trichloro-2,2,3,3-tetrafluoropropane and isomers thereof; 1,2-dichloro-3,3,3-trifluoropropane and isomers thereof; and 1,2-dichloro-1-fluoroethylene; and a co-spin agent.
Abstract:
Fibers and methods of producing fibers comprising fluorinated polymers having comonomers of tetrafluoropropene are provided. Methods may include providing a solution having a fluorinated polymer dissolved in a solvent, wherein at least one monomer of the polymer comprises a tetrafluoropropene, exposing the solution to an electrostatic field between the solution and a collection electrode, and forming fibers from the solution fluorinated polymer. Fibers may include a fluorinated polymer, wherein at least one of the monomers of the fluorinated polymer comprises tetrafluoropropene.
Abstract:
The present invention pertains to a process for manufacturing one or more fluoropolymer fibres, said process comprising the following steps: (i) providing a liquid composition [composition (C1)] comprising: - at least one fluoropolymer comprising at least one hydroxyl end group [polymer (F OH )L and - a liquid medium comprising at least one organic solvent [solvent (S)]; (ii) contacting the composition (C1) provided in step (i) with at least one metal compound [compound (M)] of formula (I) here below: X 4-m AY m (I) wherein X is a hydrocarbon group, optionally comprising one or more functional groups, m is an integer from 1 to 4, A is a metal selected from the group consisting of Si, Ti and Zr, and Y is a hydrolysable group selected from the group consisting of an alkoxy group, an acyloxy group and a hydroxyl group, thereby providing a liquid composition [composition (C2)]; (iii) submitting to at least partial hydrolysis and/or polycondensation the composition (C2) provided in step (ii) thereby providing a liquid composition [composition (C3)] comprising at least one fluoropolymer hybrid organic/inorganic composite; (iv) processing the composition (C3) provided in step (iii) by electrospinning thereby providing one or more fluoropolymer fibres; (v) drying the fluoropolymer fibre(s) provided in step (iv); and (vi) optionally, submitting to compression the fluoropolymer fibre(s) provided in step (v) at a temperature comprised between 50°C and 300°C. The invention also pertains to a process for the manufacture of said fluoropolymer fibre(s) and to uses of said fluoropolymer fibre(s) in various applications.