Abstract: A fuel hose for a resin fuel tank has a triple layer structure including a barrier layer made of an alloy material consisting primarily of EVOH and modified HDPE, and a pair of welding layers made of HDPE and formed on an inner peripheral surface and an outer peripheral surface of the barrier layer, respectively. An opening portion of the fuel hose at one end is configured in the form of an increased diameter portion and also in the form of a thick-walled portion. The increased diameter portion (or the thick-walled portion) is formed by reducing the speed of movement of dies when a hose base body is extruded into an increased diameter portion of a die surface of the dies during extrusion.

Abstract: A hose for use in bio-pharmaceutical applications includes an innermost tubular layer made from a fluoropolymer material. The tubular layer has an inner, relatively smooth and pure surface that defines an opening for transfer of various media. A layer of silicone is disposed next to an outer surface of the innermost tubular layer through use of, for example, an extrusion method. The outer surface of the tubular layer may first be modified by various treatments or chemicals to facilitate the adhesion of the silicone layer thereto. The silicone material may be solid or foamed. A reinforcement layer may be disposed adjacent to an outer surface of the silicone layer. The reinforcement layer may be formed of a wire braid having gaps. An outer jacket of silicone may be attached to the reinforcement layer and to the inner silicone layer through the gaps in the reinforcement layer.

Abstract: A prosthetic medical device exhibiting improved wear resistance is fabricated by sealing at least one polyolefinic material in an airtight container and providing an inert atmosphere within the airtight container. The polyolefinic material is exposed to an irradiation source to yield a cross-linked irradiated polyolefinic material. At least one non-irradiated polyolefinic material is blended with the irradiated polyolefinic material, and the prosthetic medical device is formed from the blended material. Selectively cross-linked polymeric compositions may be created by blending a specific amount of cross-linked resins with a specific amount of uncross-linked resins then cured into a polymeric matrix whereby the desired degree or percentage of overall cross-linking is obtained. The polymeric material may then be formed directly into a finished article by injection molding the polymeric material.

Abstract: A method of manufacturing a power transmission belt having a body with a length and a cushion rubber layer in which at least one carrying member is embedded so as to extend lengthwise of the body. The method includes the steps of: extrusion molding (a) a first rubber composition including rubber with short fibers therein and (b) a second rubber composition that is different than the first rubber composition to produce a first sheet in which the second rubber composition defines at least a part of the cushion rubber layer; applying the at least one load carrying member to the second rubber composition to produce a preform assembly; and processing the preform assembly to produce a power transmission belt.

Abstract: In a method for producing hollow fiber membranes which comprises melt kneading a mixture comprising polyvinylidene fluoride and an organic liquid or a mixture comprising polyvinylidene fluoride, an organic liquid and an inorganic fine powder, extruding the kneaded mixture to form hollow fibers, and extracting the organic liquid or the organic liquid and the inorganic fine powder from the hollow fibers, which includes the steps of drawing the hollow fibers before or after termination of the extraction and then shrinking the fibers. According to this method, it is possible to stably produce hollow fiber membranes having dense pores and having a high water permeation performance, excellent endurance and stain resistance, and which are suitable for filtration uses such as removal of turbidity of water.

Abstract: In a co-extrusion system, a primary extruder is connected to a primary flow director to direct the solid melt from the primary extruder to the co-extrusion assembly. A secondary extruder is connected to a secondary flow director to direct the melt from the secondary extruder to the co-extrusion assembly. A co-extrusion assembly produces simultaneous co-extruded melts without any significant pressure change in the melt. Dies shape the co-extruded melts to a desired shape.

Abstract: Polymer blends that exhibit good impact resistance comprise a crystalline polypropylene matrix and a partly crystalline copolymer impact modifier with a molecular weight lower than that of the matrix polymer. The matrix polymer can comprise any crystalline propylene homo- or copolymer. The impact modifying copolymers are characterized as comprising at least about 60 weight percent (wt %) of units derived from propylene and, in certain embodiments, as having at least one, preferably two or more, of the following properties: (i) 13C NMR peaks corresponding to a regio-error at about 14.6 and about 15.7 ppm, the peaks of about equal intensity, (ii) a B-value greater than about 1.4 when the comonomer content of the copolymer is at least about 3 wt %, (iii) a skewness index, Six, greater than about ?1.

Abstract: Multilayer thermoformable structures for packaging film applications. The multilayer structures having at least a first layer of polyester, a second layer of a first adhesive and a third layer of a nylon blend formed into a flexible non-oriented film by coextrusion.

Abstract: The invention relates to a method for producing shaped bodies, especially threads or foils, from at least one polymer of the groups consisting of polysaccharide, polysaccharide derivative or polyvinyl alcohol by forming a solution of the polymer that contains an additive in a solvent containing amine-N-oxide, extruding the solution and precipitating the extrudate by contacting with a coagulant. The invention is characterized in that at least two polymeric solutions are formed. At least one of the two polymeric solutions contains one or more finely distributed additives and the at least two polymeric solutions are simultaneously extruded forming a combined extrudate.

Abstract: A forming jig comprises a rectification plate having two or more material supply holes, a drawing die installed below the rectification plate to specify the external configuration of the formed body produced from a material, and a floating die in which two or more wires float vertically in spaces in the drawing die (forming pattern passages) and stretch from the exit section of the drawing die to form a hollow hole forming pattern. The forming jig and a method for producing a formed body using the jig can easily and inexpensively design or change the design of a forming pattern of hollow holes and the external configuration of the formed body and can form fine hollow holes at a high density.

Abstract: The invention provides a spinnerette assembly for forming multicomponent hollow fibers of the sheath/core type. The spinnerette assembly contains an extrusion orifice and a core forming material passage in communication with the extrusion orifice. A hollow needle extends through the extrusion orifice in a concentric manner to define an annular passage surrounding the needle. The core forming material passage includes a core forming material inlet port extending from a surface of the spinnerette assembly to an interior of the assembly and a transverse passage extending from the core forming material port to the annular passage surrounding the needle. A bore forming fluid passage communicates with the interior of the needle. The spinnerette assembly contains at least one sheath forming material passage also in communication with the extrusion orifice.

Abstract: A soft stretch yarn produced by spinning yarn of conjugate fibers including two types of polyester in which one component is PTT at a take-up velocity of at least 1200 m/min, drawing at a drawing temperature of 50 to 80° C. at a draw ratio such that the drawn yarn tensile elongation is 20 to 45%, and then heat setting.

Abstract: The present invention relates to processes for fabricating polymeric hollow fibers. Specifically, a removable solid core fiber is provided for coating one or more layers of a polymeric membrane-forming material thereon. After treating the polymeric membrane-forming material layer to form a solidified polymeric membrane having a permanent tubular shape, the solid core fiber is selectively removed, leaving an elongated lumen inside the solidified polymeric membrane, which forms a high quality polymeric hollow fiber that is substantially free of deformation defects. The solid core fiber can be made of a removable substrate material, such as water-soluble polymers polyvinyl pyrrolidone (PVP), polyvinyl alcohol (PVA), or polyethylene glycol (PEG), which are subsequently and selectively removable by water. Alternatively, the solid core fiber can be coated with a removable substrate material, which imparts removability to such solid core fiber.

Abstract: In an extrusion head and an extrusion method for the production of a tubular multilayer preform the extrusion head includes at least two feed paths for feeding plasticised plastic material from one or more extruders to an annular passage arrangement. The annular passage arrangement includes mutually concentric annular passages forming mutually separate flow paths for the various layers of the preform. An annular gap nozzle has an annular gap communicating with the annular passage arrangement, and at least one flow passage communicates with an annular passage of the annular passage arrangement, for the introduction of a translucent viewing strip. The flow passage communicates with the annular passage in question upstream of the annular gap in the region of separation of the flow paths.

Abstract: An elongate polymer member having molecular helical orientation formed by rotation immediately after passing through the extrusion head. The elongate polymer member is rotated downstream of the extrusion head in the molten state prior to solidification in order to impart the molecular helical orientation. Rotating the polymer member in the molten state allows the helical orientation to be imparted at the molecular level, and allows for more rotations per lineal foot of extrusion.

Abstract: 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.

Abstract: A rubber hose having a multilayer wall is formed of an inner layer of NBR type rubber having a high AN content, available at a low cost and highly impermeable to fuel and an outer layer of a rubber composition having a minimum Mooney viscosity of 25 to 65 at its curing temperature and highly resistant to flattening. Those layers are extruded and cured together without the aid of any mandrel owing to the inside diameter and wall thickness of the hose and the thickness of the outer layer which fall within specific ranges. This process enables the manufacture of a fuel hose having a high fuel impermeability at a low cost, while protecting its inner wall effectively from flattening during curing.

Abstract: A medical tubing is disclosed which includes a first material extending between proximal and distal ends of the tubing and which defines a lumen of the tubing. The tubing also includes a second material extending between at least portion of the distance between the proximal and distal ends of the tubing and that is embedded in the first material. The second material is fractured. The first material is flexible and the second material is relatively rigid and brittle and the two materials combined to provide a medical tubing that exhibits strain softening behavior.

Abstract: A system and method for treating pipes according to which the flexibility of the pipe is increased or maintained, or at least any decreases in the flexibility of the pipe is minimized, in relatively low temperature environments.

Abstract: Processes and apparatus for extruding a tubular film of polymer material. The apparatus comprises a circular coextrusion die having an inlet (10) for the or each component and having an exit channel (18) ending in a circular exit orifice (21) which is located radially outwardly from the die axis compared to the inlet (10). The die comprises several planar or conical die parts (5, 6, 7, 28, 29) clamped together, with surfaces supplied with grooves (14) shaped to form channels (11, 12, 13) for the flow polymer material. The shape of the channels is adapted to equalize the flow over the circumference of the exit orifice (21), and the flow of material is divided between the inlet (10) and the exit (21) into a number of part flows (13) of generally helical form with space (15) provided for overflow of material between said part flows, whereby the part are adapted so that they join to one common, circular flow.

Abstract: A method for coextruding a multilayer tubular film having a barrier material comprises (a) extruding a core extrudate of barrier material with a core extruder; (b) providing a preencapsulation die adjacent the outlet of the core extruder, the prencapsulation die capable of producing a non-uniform layer thickness; (c) extruding a preencapsular extrudate of preencapsular material and directing said preencapsular extrudate to the preencapsulation die; (d) joining the core extrudate and the preencapsular extrudate in the preencapsulation die in a coaxial relationship wherein the preencapsular extrudate is disposed radially outwardly of the core extrudate to form a preencapsulated core extrudate having a non-uniform layer thickness; (e) extruding an inner layer extrudate and an outer layer extrudate; (f) feeding the preencapsulated ore extrudate through a distribution manifold to a coextrusion die, the distribution manifold designed to overlap opposing longitudinally extending edges; and (g) forming a multilayer b

Abstract: A catheter shaft is disclosed that may reduce the thickness of the inner layer and/or may allow the reinforcing layer to share the same space as the inner lubricious layer. In one illustrative embodiment, the inner lubricious layer is removed altogether, and an inner tubular braid member defines the inner lumen of the catheter shaft. In another illustrative embodiment, the inner lubricious layer and the reinforcing layer are effectively combined to form a reinforcing member. To combine the inner lubricious layer and the reinforcing layer, the wires used to form the reinforcing braid or coil are first coated with a lubricious polymer such as PTFE or PFA. When these strands are wound to form the tubular reinforcing member, the inner surface of the reinforcing member includes a lubricious surface. Various methods are also disclosed for providing a smooth inner surface for the catheter shaft.

Abstract: Novel thermoplastic pipes which can withstand extremely high internally generated and/or applied pressures for utilization within, primarily, high pressure underground liquid and gas transport systems are provided. Such pipes are improvements over standard metal (i.e., steel, lead, and the like) pipes due to construction costs, shipping costs, implementation costs (particularly underground), modulus strength allowances to compensate for underground movements (i.e., earthquakes and tremors), non-rusting characteristics, and ease in manufacture. Such pipes are preferably reinforced with specific fabric articles which permit a lower thickness of plastic to be utilized than is generally required to withstand high pressure situations. A simplified, potentially on-site production method for producing more uniform, better-performing pipes as well as a specific molding dorn for such a purpose are also contemplated within this invention.

Abstract: The invention relates to a method of manufacturing a reinforced oblong concrete product for longitudinal load-bearing purposes, in particular a driving pile. According to the present invention reinforcing fibers are used to prevent break-up of the concrete due to radial forces which occur during driving, and the concrete composition is provided with said reinforcing fibers before the concrete composition is applied to the reinforcing wire. This method reduces the amount of heavy labour and cost. The invention also relates to a driving pile comprising reinforcing fibers.

Abstract: A manufacturing apparatus and method for multiple containment tubing produces continuous, nested tubing, or one tube within another tube, without having to fix the space between the tubes or position them concentrically. Consequently the tubing is very flexible and with uniform wall thickness. Moreover, because the inner surface of the outer tube and the outer surface of the inner tube are ribless, these kinds of features cannot interfere with the bending and twisting and the operation of the tubes comprising the tubing. The space between the tubes, or free space, has sufficient volume to contain a range of contents of the inner tube, as a safety containment device, if the inner tube ruptures, cracks, or otherwise breaks.

Abstract: The present invention discloses an extrusion die module having a flat compression seal surrounding a conical or otherwise angled spillover surface. The die module promotes a flat surface to flat surface compression seal outside of the flow distribution channels and promotes better streamlined flow and material combination than a traditional flat disk die module. The die module promotes a reduced overall diameter and wetted diameter in comparison to standard flat disk dies. In addition, the conical or angled spillover surface is surrounded by the planar sealing surface. Further, the present invention relates to a method for utilizing an extrusion die module with a conical or otherwise angled spillover surface to minimize the die surface area wetted by an intermediate layer in a multi-layer coextrusion process.

Abstract: The present invention discloses an extrusion die module having a flat compression seal and a conical or otherwise angled spillover surface. The die module promotes a flat surface to flat surface compression seal outside of the flow distribution channels and promotes better streamlined flow and material combination than a traditional flat disk die module. The die module promotes a reduced overall diameter and wetted diameter in comparison to standard flat disk dies. Further, the present invention relates to a method for utilizing an extrusion die module with a conical or otherwise angled spillover surface to minimize the die surface area wetted by an intermediate layer in a multi-layer coextrusion process.

Abstract: The present invention relates to an extrusion die assembly. Specifically, the present invention relates to an extrusion die assembly comprising a pair of extrusion dies wherein one extrusion die is disposed within the second extrusion die. The extrusion dies may comprise a plurality of extrusion die modules wherein at least one of the extrusion die modules incorporates a flat compression deal with a conical or otherwise angled spillover surface. Further, the present invention relates to a method for utilizing an extrusion die assembly comprising a pair of extrusion dies, each having at least one extrusion die module having a conical or otherwise angled spillover surface.

Abstract: The present invention discloses an extrusion die module having a flat compression seal surrounded by a conical or otherwise angled spillover surface. The die module promotes a flat surface to flat surface compression seal outside of the flow distribution channels and promotes better streamlined flow and material combination than a traditional flat disk die module. The die module promotes a reduced overall diameter and wetted diameter in comparison to standard flat disk dies. In addition, the present invention relates to an extrusion die module having a spillover surface surrounding a planar sealing surface. Further, the present invention relates to a method for utilizing an extrusion die module with a conical or otherwise angled spillover surface to minimize the die surface area wetted by an intermediate layer in a multi-layer coextrusion process.

Abstract: Using a mold equipped with a rib-forming member capable of moving forward and backward relative to the mold cavity, produced is a lightweight, hollow resin molding having a reinforcing rib structure in the hollow area, from a fiber-containing thermoplastic resin having a fiber content of from 10 to 70% by weight. To produce the molding, a melt of a fiber-containing thermoplastic resin is injected into the mold cavity or is injected thereinto under compression, then the movable mold member is moved backward in the direction in which the mold cavity is expandable, and after the start of the mold member moving, a gas is introduced into the resin melt. Even though the molding has a hollow structure and has a large surface area, it has good stiffness and high strength, and has good appearances. The weight of the molding can be well controlled and reduced to any desired degree. The molding has many applications in various fields.

Abstract: A process produces a belt-shaped member to be used in an image-forming apparatus is disclosed in which a toner image held on a latent-image-bearing member is electrostatically transferred under application of a voltage via the belt-shaped transfer member. The process includes the steps of melt-extruding a material containing a thermoplastic resin, from a circular die into a cylindrical film; forming the resultant cylindrical film by stretching in such a way that the cylindrical film comes to have a thickness smaller than the die gap of the circular die; and cutting the cylindrical film thus formed, into a seamless belt having a thickness of from 40 &mgr;m to 300 &mgr;m and a modulus in tension of 600 MPa or higher. The stretched cylindrical film is formed to have a thickness not larger than ⅓ of the die gap of the circular die. A belt-shaped transfer member may be produced by the above-described process.

Abstract: An intravascular catheter which has a lubricious catheter shaft formed from a polymeric blend comprising a thermoplastic polymeric component and a lubricious polymeric component. The lubricious polymeric component is immiscible in the thermoplastic polymeric component and exists as elongated fibers having a high aspect ratio. The lubricious component exists as a separate phase of elongated fibers which provide improved lubricity to an extruded catheter shaft formed of the polymeric blend of the invention. The aspect ratio of the lubricious component fibers is about 10 to about 100, and preferably at least about 20. The high aspect ratio of the lubricious component fibers increase the surface area of the lubricious component on the surface of the catheter shaft, and consequently increase the lubricity of the catheter shaft.

Abstract: An array of dies having a closed configuration is used in a method and apparatus for making a closed composite article that comprises multilayered materials. In the method and apparatus, at least two extruders are used to extrude at least two material streams through the die array to provide an extrudate comprised of alternate layers of material from the at least two material streams. The compositions in the two material streams can be the same or different.

Abstract: The present invention is directed to a green fluoropolymer tube which has a wall thickness of about 250 microns or less, preferably about 200 microns or less, and more preferably about 125 microns or less. With such thinness, the green tube may be formed into a tube of expanded fluoropolymer having a wall thickness of about 250 microns or less, preferably about 200 &mgr;m or less and more preferably about 125 microns or less. Such an expanded fluoropolymer tube is particularly well-suited for use as an endovascular prosthesis, such as a graft, or in a stent-graft, because of its flexibility and strength.

Abstract: A linear bearing includes a substrate and a strip of wear-resistant material. The strip is impregnated with a resin, and the impregnated strip is pultrusion bonded onto the substrate. The impregnated strip is thereby compressed upon and directly bonded to the substrate.

Abstract: An apparatus and method for spinning hollow bicomponent filaments. The apparatus includes a distributor, a spinneret having holes and a shim having openings fixed between the distributor plate and the spinneret. The distributor supplies a first polymer having an MV to a first part of the spinneret holes and a second polymer having a lower MV to a recessed section of the spinneret. The shim openings are positioned above the spinneret holes and extend away from the first part of the holes to allow the second polymer to flow from the recessed section, through the shim openings, to a second part of the spinneret holes. The two polymers travel along the opposed first and second parts of the holes until exiting the spinneret through respective asymmetric C-shaped apertures. The apertures are sized so that hydraulic split does not occur between the polymers and consequently potential filament kneeing is obviated. Upon exiting the apertures, the polymers self-join to form hollow filaments and are quenched.

Abstract: A novel technique for molding multi-layer polymer plastic articles having inner, outer and interior or core layers by controlling relative volumetric flow rates of the inner and outer layers to enable relative shifting of the position of the core, and also the relative thickness of the inner and outer layers in the molded articles; and with leading, and, where desired, trailing ends of the interior layer flow into the mold cavity substantially positioned on the zero gradient of the velocity profile of the flowing polymer streams.

Abstract: A polymer heat pipe with a carbon core and a method of forming such a heat pipe is disclosed. The heat pipe includes a substantially pure carbon fiber core and an outer jacket of substantially pure polymer material. The heat pipe is formed by extruding a mixture of a base of polymer material and a plurality of carbon fibers through an extrusion die. The extrusion die is heated into a range of approximately 250-400° F. to cause the carbon fiber to migrate to the center of the extrudate and the polymer to migrate outwardly. As a result, a jacket of polymer material is formed around a core of carbon fibers to form a highly thermally conductive heat pipe.

Abstract: A clear and printable polypropylene film is disclosed. The film is prepared from a blend of a polypropylene and an ethylene/alkyl acrylate copolymer. It has an excellent adhesion with commonly used inks without surface treatment.

Abstract: Novel thermoplastic pipes which can withstand extremely high internally generated and/or applied pressures for utilization within, primarily, high pressure underground liquid and gas transport systems are provided. Such pipes are improvements over standard metal (i.e., steel, lead, and the like) pipes due to construction costs, shipping costs, implementation costs (particularly underground), modulus strength allowances to compensate for underground movements (i.e., earthquakes and tremors), non-rusting characteristics, and ease in manufacture. Such pipes are preferably reinforced with specific fabric articles which permit a lower thickness of plastic to be utilized than is generally required to withstand high pressure situations. A simplified, potentially on-site production method for producing more uniform, better-performing pipes as well as a specific molding dorn for such a purpose are also contemplated within this invention.

Abstract: A method of producing a hose-connector assembly, including the steps of forming by extrusion an inner resin tube layer, forming by extrusion an outer rubber protector tube layer having substantially the same length as the inner resin tube layer, so as to cover the outer surface of the inner resin tube layer over the entire length of the inner resin tube layer, to obtain a laminar tubular blank consisting of the inner resin tube layer and the outer rubber protector tube layer, cutting the laminar tubular blank into pieces, and press-fitting an end portion of a tubular connector in each of at least one of the opposite end portions of the inner resin tube.

Abstract: The present invention is directed to a method of making a substantially continuous filament web which includes providing a plurality of polymer extruders for supplying polymer streams of at least two different polymer compositions, and providing a spinneret assembly for receiving the polymer streams. The spinneret assembly includes a plurality of orifices from which the polymer streams are extruded for formation of substantially continuous filaments formed from the polymer compositions. The distribution of at least one of the polymer compositions within the spinneret assembly is selected to optimize selected physical characteristics of the resultant continuous filament web.

Abstract: The invention provides a spinnerette assembly for forming multicomponenthollow fibers of the sheath/core type. The spinnerette assembly contains an extrusion orifice and a core forming material passage in communication with the extrusion orifice. A hollow needle extends through the extrusion orifice in a concentric manner to define an annular passage surrounding the needle. The core forming material passage includes a core forming material inlet port extending from a surface of the spinnerette assembly to an interior of the assembly and a transverse passage extending from the core forming material port to the annular passage surrounding the needle. A bore forming fluid passage communicates with the interior of the needle. The spinnerette assembly contains at least one sheath forming material passage also in communication with the extrusion orifice.

Abstract: A method of continuously insulating a body of substantially uniform cross-section, such as a pipeline, so that it can be either wound on a reel for transportation to a site where it can then be unreeled, or by allowing the application of the insulation on location as the pipeline is unreeled.

Abstract: The invention provides a spinnerette assembly for forming hollow fibers. The spinnerette assembly contains an extrusion orifice and a fiber-forming material passage in communication with the extrusion orifice. A hollow needle extends through the extrusion orifice in a concentric manner to define an annular passage surrounding the needle. The fiber-forming material passage includes a fiber-forming material inlet port extending from a surface of the spinnerette assembly to an interior of the assembly and a transverse passage extending from the fiber-forming material port to the annular passage surrounding the needle. A bore forming fluid passage communicates with the interior of the needle.

Abstract: An apparatus for continuously producing composite structural beams is disclosed. The invention includes novel apparatus for producing a continuous lightweight composite beam by combining solid pultruded cap sections with composite sandwich panels. The invention further provides novel means by which pultruded composite tubular structural elements can be made of composite materials, wherein the tubular elements include solid pultruded corners.

Abstract: A method and device for forming composites using a pre-consolidated tubular braid (i.e., a braid removed from the braiding machine on which it was produced prior to use in further processing) including feeding the pre-consolidated tubular braid over a supporting mandrel, impregnating the braid with a resin using a pressurized resin injection chamber with a mandrel adapted to provide adequate impregnation, feeding the resin saturated braid into a pultrusion die with a mandrel for forming and heating and pulling the cured composite from the die for finishing the end product.

Abstract: A rubber hose having a multilayer wall is formed of an inner layer of NBR type rubber having a high AN content, available at a low cost and highly impermeable to fuel and an outer layer of a rubber composition having a minimum Mooney viscosity of 25 to 65 at its curing temperature and highly resistant to flattening. Those layers are extruded and cured together without the aid of any mandrel owing to the inside diameter and wall thickness of the hose and the thickness of the outer layer which fall within specific ranges. This process enables the manufacture of a fuel hose having a high fuel impermeability at a low cost, while protecting its inner wall effectively from flattening during curing.

Abstract: Improved polymer blends, and polymer blend membranes having improved mechanical properties are provided by alteration of the critical solution temperature of the polymer blend spinning solution through the incorporation of organic or inorganic complexing agents.

Abstract: Methods are disclosed for producing multi-layer peelable sheaths having formed tips, for use as medical introducer devices, e.g., sheaths for inserting a catheter or the like into a patient. The methods include the steps of preparing a first composition blend for forming an inner layer of the multi-layer sheath, preparing a second composition blend for forming an outermost layer of the multi-layer sheath, combining the first and the second composition blends into a multi-layer pre-form, processing the multi-layer pre-form for producing tubing, and forming a tip at one end of the tubing using a thermal process, thereby producing the multi-layer sheath having the inner layer, the outermost layer, and the formed tip. The methods of the present invention include adding a detectable material to the blend used for making the inner layer for facilitating external visualization of the multi-layer sheath, thereby achieving a sheath with a formed tip having no visible discoloration.