1678results about "Hollow filament manufacture" patented technology

A medical balloon composed of a micro-composite material which provides for radial expansion of a balloon to a predetermined extent, but which has minimal longitudinal growing during balloon inflation. The micro-composite material includes a fibril component, a matrix component, and optionally, a compatibilizer. The fibril component may preferably be liquid crystal polymer fibers randomly scattered through out the balloon material. The liquid crystal polymers are created by extrusion at high speed. An alternative fibril component may be a PET fibers which are uniformly spaced about the balloon material and extend through out the length of the balloon material tube.

Polymeric composite stents reinforced with fibers for implantation into a bodily lumen are disclosed.

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.

A polyester container made from a polymer having ethylene glycol moieties, isosorbide moieties and terepthaloyl moieties, and the method of making the container is described. The polyester container is suitable for holding liquids and solids, and may be hot-filled or cold-filled. In particular, wide-mouth jars and narrow-necked bottles may be formed. The polyester has an inherent viscosity of at least 0.35 dL/g when measured as a 1% (weight/volume) solution of the polyester in o-chlorophenol at a temperature of 25 DEG C.

A method for electrospinning nanofibers having a core-sheath, tubular, or composite structure is disclosed. The process uses a spinneret having first and second capillaries that channel first and second fluids in the spinneret, the second capillary surrounding the first. A high voltage is applied between the spinneret and a spaced conductive collector. In one embodiment, the first fluid is a mineral oil and the second fluid is a polymeric solution that may include a polymer, a catalyst, a solvent, and a sol-gel precursor. The as-spun nanofiber includes an oil core and a composite sheath. The oil may be removed to produce a composite tubular fiber or the polymer and oil may be removed by calcination to produce a ceramic tubular fiber. In other embodiments, miscible fluids are used to produce porous nanofibers, selected additives functionalize the surfaces of the nanofibers and/or conjugated polymers are used.

A hollow fiber microfiltration (MF) membrane is provided. The casting solution used to make this membrane includes a fiber-forming polymer having a degree of polymerization greater than about 1000, a water-soluble polymer, an anhydride with about 2 to 12 carbon atoms, and a solvent. The membrane is formed by mixing and heating these components to form a viscous dope and then extruding the dope through an annular orifice to form a hollow fiber MF membrane. The hollow fiber membrane is then fed through a coagulation bath and two leaching baths. The membrane is especially useful for filtering liquids, such as wine and juice, so as to remove bacteria, gel, and solid particles from the liquids.

A stent formed of polymeric material, useful for the expansion of a lumen and the delivery of one or more therapeutic agents in situ is disclosed. The stent may be multi-layered, and may change shape at a state transition temperature governed by the materials forming the layers. Methods of use and manufacture are also disclosed.

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.

Disclosed is a process for the preparation of shaped articles such as, for example, sheeting, films, tubes, bottles, preforms and profiles, having high transparency and low haze, and comprising immiscible blends of at least one polyester comprising 2,2,4,4-tetramethyl-1,3-cyclobutanediol, and a copolyamide or a transamidized, homogeneous blend of a least two polyamides. The components of the immiscible blend have refractive indices which differ by about 0.006 to about −0.0006. The small difference in the refractive indices enable the incorporation of regrind into the polymer composition to produce transparent shaped articles. These articles may have one or more layers and can exhibit improved excellent barrier properties and good melt processability while retaining excellent mechanical properties. Metal catalysts can be incorporated into the compositions to produce shaped articles having oxygen-scavenging properties.

The invention relates a nylon 6 polymerization method and a direct spinning method of a melt of a polymer obtained with the nylon 6 polymerization method. A polyamide 6 prepolymer is prepared at the low temperature, the content of oligomers in the melt is controlled in advance, polymerization is completed before a large quantity of cyclic oligomers are generated with a condensation polymerization dynamic strengthening method, a nylon 6 polymer melt with certain molecular weight is acquired, the content of extracts in the product is smaller than or equal to 1.5 wt%, and the content of cyclic dipolymers is smaller than or equal to 0.2wt%; then, direct melt spinning forming is performed after condensation polymerization dynamic strengthening ends. The process is simple, energy consumption is further reduced while the utilization rate of caprolactam is increased, the obtained melt can be directly used for melt spinning, high-capacity large-scale production is easy to realize, a modifier can be added in the polymerization process, flexible production of nylon 6 is realized, and the nylon 6 can be applied to fibers for clothes, industrial filaments, engineering plastics and other fields.

Disclosed is a process for the preparation of shaped articles such as, for example, sheeting, films, tubes, bottles, preforms and profiles, having high transparency and low haze comprising immiscible blends of one or more thermoplastic polymers selected from polyesters, polycarbonates, and polyarylates, and a copolyamide or a transamidized, homogeneous blend of a least two polyamides. The components of the immiscible blend which have refractive indices which differ by about 0.006 to about −0.0006. The small difference in the refractive indices enable the incorporation of regrind into the polymer composition to produce transparent shaped articles. These articles may have one or more layers and can exhibit improved excellent barrier properties and good melt processability while retaining excellent mechanical properties. Metal catalysts can be incorporated into the compositions to produce shaped articles having oxygen-scavenging properties.

Cellulosic fibers having enhanced reversible thermal properties and applications of such cellulosic fibers are described. In one embodiment, a cellulosic fiber includes a fiber body including a cellulosic material and a set of microcapsules dispersed in the cellulosic material. The set of microcapsules contain a phase change material having a latent heat of at least 40 J/g and a transition temperature in the range of 0° C. to 100° C., and the phase change material provides thermal regulation based on at least one of absorption and release of the latent heat at the transition temperature. The cellulosic fiber can be formed via a solution spinning process, and can be used in various products where thermal regulating properties are desired.

An implantable, radially distensible stent includes a tubular structure having opposed open ends. The wall of the stent is made from a shape memory polymeric material. Grooves may be disposed within an outer surface of stent wall to improve flexibility and drainage of the stent.

The invention relates to a terpolymer of tetrafluoroethylene (TFE) monomer, polyvinylidene fluoride (PVDF) monomer and hexafluoropropylene (HFP) monomer for forming an ultrafiltration or microfiltration membrane, method of forming said membranes, and to the ultrafiltration or microfiltration membranes themselves. The invention also relates to a method of forming a polymeric ultrafiltration or microfiltration membrane including preparing a leachant resistant membrane dope which incorporates a leachable pore forming agent, casting a membrane from the dope and leaching the pore forming agent from the membrane. The invention also relates to a method of preparing a polymeric ultrafiltration or microfiltration membrane of improved structure including the step of adding a nucleating agent to the membrane dope before casting.

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 fibre 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 porous hollow fiber membrane having a particle cutoff within the range of 1 to 10 μm and a pure water permeate flow equal to or higher than 30,000 L/m²/hr/100 kPa. This porous hollow fiber membrane can be prepared by a method including, while a spinning dope containing a base polymer as a material for forming the porous hollow fiber membrane, an additive used for facilitating a phase separation of the spinning dope, a solvent compatible with both the base polymer and the additive and a mass of microparticles insoluble to the compatible solvent and uniformly dispersed in a liquid medium and having an average particle size within the range of 1 to 20 μm, and a coagulating liquid for forming the hollow fiber membrane is used, a step of forming the hollow fiber membrane according to a dry-wet spinning method or a wet spinning method, and a step of extracting and removing the microparticles by immersing the hollow fiber membrane, which has been spun, into an extracting solution effective to dissolve the microparticles, but ineffective to dissolve the base polymer.

A method for dispersing sepiolite-type clay particles in a polyester matrix by melt-compounding a mixture of: sepiolite-type clay, at least one linear polyester oligomer, and at least one polyester polymer to produce a nanocomposite composition; and, optionally, subjecting said nanocomposite composition to solid state polymerization to increase polyester molecular weight. Further described is a method for preparing a polyester nanocomposite composition from a masterbatch, comprising melt-compounding a mixture of: sepiolite-type clay, at least one polyester oligomer, and at least one polyester polymer to produce a nanocomposite composition containing a greater concentration of sepiolite-type clay than is desired in the final resin composition; optionally, subjecting said nanocomposite composition to solid state polymerization to increase the polyester molecular weight; and further melt compounding said nanocomposite composition with polyester polymer and, optionally, additional ingredients.

Tapered layers of pre-cured composite material are integrated into a tapered, highly stressed laminate structure in order to provide improved compressive strength. The pre-cured composite material can advantageously be cured under tension as pultruded material, to further augment compressive strength. The thickness of composite layers can be tapered on their termination edges by mechanically abrading, chemical abrading, or other methods. Especially preferred embodiments include aircraft structural components such as wings, wing spars, wing skins, fuselage skins, rotor blades, propellers, and propeller blades. Preferred laminates can be constructed to have at least 6, 10, 30, 50, or 100 layers of material, and can have a maximum thickness of at least 0.15, 0.25, 0.5, 1.0, or 5.0 inches.

An apparatus and method for providing a co-extruded, tapered multi-layer shaft. A co-extruded, tapered multi-layer shaft may be fabricated by selecting a first material for the inner layer of the shaft and a second material for the outer layer of the shaft. The first and second materials are then co-extruded by a co-extrusion system including a puller with programmable tapering capabilities. The system forms a hollow tubing having an inner layer and an outer layer, wherein the tubing has the desired tapered characteristics. The result is a tapered tubular shaft having an inner layer and an outer layer.

A method of making a disposable tubular device comprising extruding a first material through a first die to form the tube and moving the tube through the second die while extruding a second material through the second die to form the tube-support structure. The second material has a surface hardness which is greater than the surface hardness of the first material.