1685results about "Hollow filament manufacture" patented technology

Porous polymeric membranes including Halar (poly (ethylene chlorotrifluoroethylene)) and related compounds and the methods of production thereof which avoid the use of toxic solvents. Preferred solvents, coating agents and pore forming agents are citric acid ethyl ester or glycerol triacetate. The membranes may be in the form of a hollow fiber or flat sheet, and may include other agents to modify the properties of the membrane, such as the hydrophilic / hydrophobic balance. Leachable agents may also be incorporated into the membranes.

A catheter assembly includes an inner liner made of flexible material and an outer layer having a steering mechanism. The steering mechanism includes at least one flat wire and a corresponding lumen through which the flat wire may travel. The steering mechanism may also include at least one pull ring to which the flat wires are attached. A layer of heat shrink material may encompass the outer layer. A braided wire assembly may also be provided in the outer layer, and may be formed by braiding a plurality of flat wires into a wire mesh. The overall cross-section of the catheter assembly is preferably substantially circular. A catheter shaft may include a plurality of segments of differing hardness characteristics. The outer layer typically comprises a melt processing polymer such that the catheter assembly may be laminated using heat.

Fiber spinning of two polymer compositions wherein one of the compositions contains carbon nanotubes produces structures such as fibers, ribbons, yarns and films of carbon nanotubes. The polymers are removed and stabilization of the carbon nanotube material is achieved by post-spinning processes. The advances disclosed herein enable the carbon nanotube composites to be used in actuators, supercapacitors, friction materials and in devices for electrical energy harvesting.

Methods for forming a tube that includes a feature extending from an inner surface of the tube are provided. The methods can include using a die and stamper, single impact extrusion, double impact extrusion, and progressive deep draw process.

A mandrel assembly that includes an elongated hollow structure comprising a thermoplastic material that is extrudable having a first end and a second end. A first end cap attached to the first end. A vent tube attached to the first end cap, the vent tube extending from the first end cap. A second end cap attached to the second end. The mandrel assembly adapted to shape and form a composite structure in or outside an autoclave.

The invention belongs to a material with a micro / nano composite structure, and particularly relates to a core / shell fiber with a nanowire-embedded microtube structure and a preparation method thereof. The core / shell fiber is characterized in that independent nanowires are embedded in a microtube with a micron-level hollow tubular structure; and the microtube material and the nanowire material arethe same or different polymer materials or inorganic oxide materials. The preparation method provided by the invention is a three-fluid coaxial electrostatic spinning method, wherein three stainless steel spray tubes with different thicknesses are coaxially assembled into a spinneret, and corresponding liquid is respectively introduced into each spray tube through a liquid supply system to carry out composite electrospinning, thus forming a fiber with a three-layer core / shell structure; and moreover, the middle-layer material is removed to leave the hollow tubular structure, thus obtaining the core / shell fiber with a nanowire-embedded microtube structure. The three-fluid composite electrostatic spinning method provided by the invention is more suitable for the preparation of the core / shell fiber.

Disclosed are implantable or insertable medical devices that provide resistance to microbial growth on and in the environment of the device and resistance to microbial adhesion and biofilm formation on the device. In particular, the invention discloses implantable or insertable medical devices that comprise at least one biocompatible matrix polymer region, an antimicrobial agent for providing resistance to microbial growth and a microbial adhesion / biofilm synthesis inhibitor for inhibiting the attachment of microbes and the synthesis and accumulation of biofilm on the surface of the medical device. Also disclosed are methods of manufacturing such devices under conditions that substantially prevent preferential partitioning of any of said bioactive agents to a surface of the biocompatible matrix polymer and substantially prevent chemical modification of said bioactive agents

The invention discloses a method for preparing PAN (polyacrylonitrile)-based porous hollow carbon fibers by coaxial electrospinning. The method includes the steps: mixing polyacrylonitrile with additives to serve as outer solution; taking inner polymer to serve as inner solution; inputting the outer solution and the inner solution into outer layers and inner layers of coaxial needles respectively at the constant flow velocity and in the constant velocity ratio for electrospinning so that PAN-based sheath-core composite fibers are obtained; and subjecting the PAN-based sheath-core composite fibers to washing, pre-oxidation and carbonization so that the PAN-based porous hollow carbon fibers are obtained. The PAN-based porous hollow carbon fibers combine structural characteristics of original porous carbon fibers and original hollow carbon fibers, the specific surface area of the fibers can be greatly increased, and use efficiency of materials is improved. When the PAN-based porous hollow carbon fibers prepared by the method are applied to gas adsorption, gas can enter hollow portions of the fibers more easily, so that adsorbability is enhanced while time required by adsorption is shortened.

A tubular tissue scaffold is described which comprises a tube having a wall, wherein the wall includes biopolymer fibrils that are aligned in a helical pattern around the longitudinal axis of the tube where the pitch of the helical pattern changes with the radial position in the tube wall. The scaffold is capable of directing the morphological pattern of attached and growing cells to form a helical pattern around the tube walls. Additionally, an apparatus for producing such a tubular tissue scaffold is disclosed, the apparatus comprising a biopolymer gel dispersion feed pump that is operably connected to a tube-forming device having an exit port, where the tube-forming device is capable of producing a tube from the gel dispersion while providing an angular shear force across the wall of the tube, and a liquid bath located to receive the tubular tissue scaffold from the tube-forming device. A method for producing the tubular tissue scaffolds is also disclosed. Also, artificial tissue comprising living cells attached to a tubular tissue scaffold as described herein is disclosed. Methods for using the artificial tissue are also disclosed.

Disclosed is a hollow fiber that includes a hollow positioned at the center of the hollow fiber, macropores positioned at adjacent to the hollow, and mesopores and picopores positioned at adjacent to macropores, and the picopores are three dimensionally connected to each other to form a three dimensional network structure. The hollow fiber includes a polymer derived from polyimide, and the polyimide includes a repeating unit obtained from aromatic diamine including at least one ortho-positioned functional group with respect to an amine group and dianhydride.