Abstract: A method and apparatus for making filter elements in which a mixture of activated carbon granules and fibers are processed with meltable polymer fibers to form a porous element. The density of the porous structure increases in a direction from the periphery thereof to its center. Also, the article formed by the method using the apparatus.

Abstract: An extrusion molding apparatus for a ceramic molded product which is capable of passing a ceramic material smoothly through a filter unit is disclosed. The extrusion molding apparatus comprises a mold (11) for molding a ceramic molded product, a screw extruder (4) for supplying a ceramic material (80) to the mold (11), and a filter unit (3) for filtering the ceramic material (80) at the extrusion outlet (41) of the screw extruder (4). The screw extruder (4) has built therein a screw (40) for kneading while at the same time leading the ceramic material (80) forward, and further has, on the front part thereof, a spatula portion (5) adapted to move over the inlet surface (30) of the filter unit (3) and there is a predetermined distance D between the spatula portion and the inlet surface (30).

Abstract: A tubular, multilayer film comprises a central barrier layer and a pair of adhesive layers on opposite sides of the central barrier layer. The adhesive layers completely cover the central barrier layer. Opposing edges of the central barrier layer overlap longitudinally along the tubular, multilayer film. The total thickness of the central barrier layers in the overlapping portion is substantially the same as the thickness of the central barrier layer in the non-overlapping portion. The tubular, multilayer film also includes inner and outer surface layers. The inner surface layer extends completely around the interior of the tubular, multilayer film, and the outer surface layer extends completely around the exterior of the tubular, multilayer film.

Abstract: In an extrusion die flow channels supply molten plastic to a pair of distribution grooves constructed in the upstream face of the die component adjacent to the die body. The die body becomes more universal and can be used for a variety of applications by replacing the die component with alternate designs of distribution grooves.

Abstract: An extrusion die for forming a cellular honeycomb structure having a finned protrusion extending from at least one cell wall of the honeycomb structure. The extrusion die is a composite extrusion die that comprises a primary extrusion die body having an inlet face and an outlet face, and at least a first insert member that is secured into a first intersection formed by a pair of intersecting slots at the outlet face of the primary extrusion die body. More preferably, a plurality of insert members are secured into a plurality of intersections, each intersection being formed by a pair of intersecting slots and each of the intersections being defined by four pegs/pins at the outlet face of the primary extrusion die body.

Abstract: A method of removing a core from a CMC component in which the core was used to form an internal cavity. According to one embodiment of the invention, the core is removed from a fully densified CMC component by heating the component and core to a temperature at which the core deteriorates but below a temperature at which the component would melt or otherwise be damaged. According to a second embodiment of this invention, the component is only partially densified, and then impregnated with a coating material that is resistant to a leaching compound capable of removing the core. The core can then be removed using the leaching compound without damage to the internal surfaces of the component defined by the core when the component was fabricated.

Abstract: A pipe molding die of the present invention is capable of rectifying a flow of a molten resin by a resin reservoir and uniformizing the flow of the resin extruded from the die in whichever position in a peripheral direction on a flow path within the die. Consequently, ununiformity in wall thickness of the resin pipe to be molded can be eliminated. The pipe molding die comprises a throttle part as one of components thereof, which includes a core, a shell part fitted to the core and a resin reservoir as a portion of a flow path which is formed between the core and the shell part. A molten, resin as a pipe raw material flows through the flow path. The resin reservoir is provided in at least one of the core and the shell part, and takes a ring-like shape circumscribing a central axis of the pipe molding die with the central axis centered. The resin reservoir assumes a recessed shape in cross-section.

Abstract: A die for extruding ceramic honeycomb structural bodies, have a plurality of ceramic batch discharge slits, a plurality of ceramic batch supply holes communicated with the ceramic batch discharge slits, and a plurality of pipes fitted into at least some of the ceramic batch holes. In the die, the pipes are inserted into the ceramic batch supply holes in such a manner that tip portions of the pipes are located apart from bottom portions of the ceramic batch supply holes.

Abstract: Honeycomb extrusion dies for the extrusion of honeycomb ceramics of high cell density and reduced cell wall thickness are machined from fully consolidated powder metallurgy (P/M) stainless steels, providing dies with reduced feed hole roughness, improved feed hole straightness, and superior discharge slot finish, with the result that significantly enhanced extrusion performance and higher quality honeycomb extrusions are realized.

Abstract: An extrusion die for making shaped extrudate products has structure which defines a central duct which is convergent from a duct inlet opening to a duct outlet opening and has structure which defines a tubular extrusion duct co-axial with the central duct and which also is convergent from a duct inlet opening to a duct outlet opening. A feed diaphragm member has a portion which converges to an opening which opens to a distribution chamber which diverges so that substance being extruded is distributed to the central and tubular ducts. Diaphragms are provided in the ducts to delimit passage of extrudate substance into the ducts. Additionally, members are provided for altering the position of the central duct and its duct outlet relative to the second duct member and its outlet.

Abstract: The present invention is directed to a plant for performing a process for manufacturing a plastic composite profile of any cross section, having an outer layer or skin made of a first material and at least one inner layer made of a different material suitable for adhering to the skin, according to which process the materials of the profile are coextruded. In a first step, a cylindrical bead of solid cross section is produced using a coextrusion unit, in which bead the skin material forms an outer ring whereas the material of the inner layer forms the core; and, downstream of the coextrusion unit, the cross section of the cylindrical bead is gradually converted in a simple extrusion head, of the kind used for single-material profiles, into the desired section for the profile, in such a way that the skin remains present, with a minimal thickness, at least on all the essential parts of the completed profile.

Abstract: An extruder die head, preferably a blown film head, comprises an internal cylindrical mandrel and a jacket, which envelops concentrically said mandrel. Between said mandrel and jacket an annular channel is formed that empties into a die slit. The invention also comprises at least one line, which empties into the annular channel in the area opposite the die slit and which feeds a melt. To prevent a slit between the central mandrel and the jacket, enclosing said mandrel, where the polymer melt could accumulate and deposit, the mandrel is made as one piece with a flange-shaped foot. The jacket rests with its bottom face sealingly on the annular surface of the flange-shaped foot and is connected, for example fastened, to the same. The annular channel extends from the peripheral surface of the mandrel to the flange-shaped foot up to and into the transition region. The line, feeding in a melt, empties into this transition region.

Abstract: Method and apparatus for the continuous extrusion of rods of plastic raw material. The rods contain at least one inner channel which is at least in part spiral-shaped. The raw material may be a powder-metallurgical or ceramic mass. The material is extruded through a nozzle mouthpiece and made to rotate by an arrangement of flow guiding surfaces. At least one thread made of a flexible or elastic material is entrained and gives the rod a spiral shape with a predetermined pitch. The thread is retained upstream of the nozzle mouthpiece in an eccentric position relative to the rod axis that extends through the nozzle mouthpiece. The movement of rotation of the raw material is adjusted by an outer adjusting force which modifies the angle between the arrangement of flow guiding surfaces and the longitudinal axis of the nozzle mouthpiece to adjust the position and pitch of the spiral channel.

Abstract: The present invention relates to an apparatus for producing pipes of a moldable material, preferably plastic, comprising an extruder, a cylindrical mold comprising chill molds (4, 5), a mandrel (8) inside the extruder and a kernel (9) as an extension of the mandrel. The mandrel is attached at its front end to the extruder. The mandrel (8) and the kernel (9) can be kept concentric with the extruder and the mold if the mandrel and the kernel are joined to each other in such a manner that the angle between their center lines is adjustable.

Abstract: The invention relates to an extrusion die for the manufacture of monolithic adsorption tubes having a solid body portion with a multiplicity of tunnels for the passage of gas. The die comprises a multiplicity of rods positioned within an outer cylindrical housing and oriented parallel thereto. The rods are supported near the entrance end of the housing, by at least two sets of ribs, each set of ribs arranged in a geometric pattern and oriented perpendicular to the cylindrical housing. The rods provide the form for tunnels in the extruded monolithic adsorption tube.

Abstract: A honeycomb extrusion die 1 for extruding a honeycomb structural body, having: a plurality of intersecting slits 2 arranged in a front surface thereof, each of the slits 2 being formed by cell blocks 3; a plurality of raw material feeding holes 4 arranged in a back surface thereof, each of the raw material feeding holes 4 being communicated with the slits 2; and a round portion formed in corners 3a of each of the cell blocks 3; is disclosed. In the honeycomb extrusion die 1, each of the cell blocks 3 includes, a cell block body 11, a first coating layer 12 formed by electroless plating on the cell block body 11, and a second coating layer 13 formed by chemical vapor deposition on the first coating layer 12, and a width of each of the slits is 45-120 &mgr;m.

Abstract: An extrusion die for extruding biodegradable material, the extrusion die including: a mandrel; an outer member positioned near the mandrel; an extrusion orifice between the mandrel and the outer member; a member in communication with at least one defining member of the extrusion orifice, wherein the member is capable of producing relative movement between the outer member and the mandrel, wherein the relative movement has a component transverse to an extrusion direction of biodegradable material through the extrusion orifice; a flow control device which controls flow of biodegradable material through the extrusion die; and a positioning device which positions the outer member and the mandrel relative to each other.

Abstract: A diverter element is constructed of a generally cylindrical shape for insertion in an open cylindrical bore. A balanced flow passage is formed by the cooperation of grooves constructed on the outer surface of the diverter and the inner surface of the bore. A distribution groove is constructed in the diverter extending circumferentially about the diverter surface. First and second pairs of diverging grooves are constructed downstream of the distribution groove. The diverging grooves are separated by a dam which is shaped to restrict flow at the point of divergence of the grooves to encourage the plastic flow to divide and fill the diverging grooves while allowing reduced flow over the dam.

Abstract: An apparatus for extruding plastic materials in multilayer tubular form includes an annular extrusion die having an annular extrusion orifice and annular passage for conveying plastic material to the extrusion orifice, the die also having at least one arcuate passage extending at least partly around the annular passage such that the arcuate passage completely surrounds, or where there is more than one arcuate passage in combination completely surround, the annular passage inwardly or outwardly thereof and is or are in communication therewith. A melt stream of plastic material is encapsulated with a different plastic material in a circumferentially continuous manner to produce an encapsulated melt stream, and at least a portion of the encapsulated melt stream is fed to an arcuate passage to cause at least partially encapsulated plastic material to pass into the annular passage with subsequent extrusion in multilayer tubular form from the annular die orifice.

Abstract: An extrusion die for extruding biodegradable material into a flexible, pliable and non-brittle structure, the extrusion die including: a cylindrical mandrel; a cylindrical outer ring positioned concentrically around the mandrel; an annular extrusion orifice between the mandrel and the outer ring; and a flow control device which controls flow of biodegradable material through the extrusion die, wherein the flow control device comprises a mechanism which translates the outer ring to adjust the width of the annular extrusion orifice, and wherein the flow control device further includes a flow control channel upstream of the extrusion orifice which throttles flow of the biodegradable material through the die.

Abstract: In an extrusion die flow channels supply molten plastic to a pair of distribution grooves constructed in the upstream face of the die component adjacent to the die body. The die body becomes more universal and can be used for a variety of applications by replacing the die component with alternate designs of distribution grooves.

Abstract: A spider in an extruder head has a plurality of internal plastic flow passages extending axially through the spider and a spider leg between each flow passage. Each spider leg has upstream and downstream spider leg parts. The upstream part is a flow splitter which splits flow of plastic along the extruder to the spider leg into a plurality of independent plastic streams. The downstream part of the spider leg has a plurality of flow guides staggered at different radial depths in the spider leg with all of the flow guides being directed at one another to guide the bonding of independent plastic streams.

Abstract: The invention relates to a cross discharge head for extrusion equipment comprising a housing to be mounted on an extruder, which in its interior receives an annular feeding channel encompassing a passage, disposed in the housing and disposed at an angle to the direction of extrusion of the extruder, for the supply of a product to be ensheathed with the extrudate, which receives in its interior a distributor piece, and which at the exit is provided with annular outer shaping tools tapering the stream of extrudate, which are secured on the front face of the housing so as to be exchangeable, wherein the passage at the end side is encompassed by a conical guidance nipple whose outside is simultaneously also the inner shaping tool.

Abstract: A coextrusion die includes a plurality of annular cells stacked on top of each other. Each annular cell includes a plurality of openings aligned with openings in the adjacent cell, thus forming multiple streams. Plastic melt may be supplied to the die coplanarly. Stacks of annular disks may be joined to form the annular cells through which plastic melt can be axially directed.

Abstract: A paste extruder includes a machine frame; an extrusion barrel seated in the machine frame and having an open end; an extrusion die connected to the open end of the extrusion barrel; and a mandrel rod which is arranged coaxially inside of the extrusion barrel, which has a mandrel tip, and which cooperates with the extrusion die, wherein the mandrel rod is comprised of a mandrel rod tube and an inner mandrel having a portion positioned proximate to the extrusion die which projects from the mandrel rod tube and having a portion arranged inside of the mandrel rod tube which has a first section arranged at a radial distance from the mandrel rod tube, and which has a second section rigidly connected with the mandrel rod tube, and wherein the first section has an elastic element which acts transversely to one of the axial direction or the direction of extrusion.

Abstract: A die for the preparation of a toner resin in an extruder having a housing defining a housing aperture therein and a conveyor for conveying the resin through the housing aperture to form a stream of resin is provided. The die includes a member connected to a first end of the housing. The member defines an opening therethrough. The cross sectional area of the opening is progressively reduced in the direction of the stream of resin for at least a substantial portion of the opening.

Abstract: This invention relates to a Multi-Layer Blown-Film Extrusion Die. An Extrusion Die is a key component of extrusion equipment, used in manufacture of Blown film for packaging industry. Although this Extrusion Die relates to production of five or more layers of blown films, it can also be used for production of lesser number of layers. While in the conventional outside fed die, melt was to be conveyed around the die in a fanning-out configuration, in this invention the polymer melt is split into two streams, before being fanned or spread around the circumference. Polymer melt enters several spiral or helical grooves prior to joining the gap that enjoins melt with other layers of the melt streams. The dimensions of spiral grooves and lands are carefully calculated, keeping in view relevant factors such as melt viscosity, shear sensitivity temperature and pressure requirements etc.

Abstract: A die body of a die assembly for extruding plastic in tubular layers is constructed having primary and secondary balanced flow paths for two layers of extruded plastic. The primary flow path delivers plastic to a distribution groove in the die body which communicates with a first extrusion channel. A tip die is designed to receive flowing plastic from the secondary flow path of the die body and deliver such plastic to a distribution groove which communicates with a second extrusion channel.

Abstract: Aa apparatus for manufacturing profile extrusion molded articles having a gradually transforming portion at which its cross section gradually changes includes a stationary die block having an aperture in a shape of the maximum cross section of the gradually transforming portion and a resin passage in communication with the aperture, an extruder extruding resin material of a gradually changing amount to an inlet of the resin passage, and flow direction controlling means for changing a flow direction of the resin material flowing within the resin passage in accordance with the extruding amount of the resin material. The manufacturing apparatus can produce profile extrusion molded articles without any bypass passage, avoid the resin material to be discharged outside the stationary die block, and prevent unsightly lines tracing a shutter movement from appearing on the design surface of the extrusion molded articles.

Abstract: An extruded "Y" or bifurcated tube having unitary construction and an extrusion apparatus therefor. The "Y" tube includes three separate tubes, each tube having a central lumen, and a transition portion integral with the tubes and providing physical connection and fluid communication between the individual lumens of the three separate tubes. The first of the three tubes has a first lumen and is first formed by extrusion through a convention extruding die. The extruder die then gradually bifurcates the first tube, providing a gradual transition between the first tube and the second and third tubes. The lumens in the second and third tubes thus formed remain in uninterrupted fluid communication with the lumen of the first tube. The bifurcation takes place with the first tube to form second and third tubes smoothly and over a transition distance which is easily controlled by the extruder die. The bifurcated second and third tubes are continuous with the first tube making the "Y" tube unitary.

Abstract: An extruding apparatus for producing a honeycomb structure having cell walls and a skin. The apparatus includes a die (10) and a mask (20). The mask (20) is of an annular shape of an inner diameter (D1) and is located on an annular recess formed by a taper surface (19) and an outlet end surface (18b) of the die. The mask (20) has a top surface (21), which is in contact with an outlet end surface (18b) of the die (10), so that the degree of the opening of feed holes (11a), (11b) and (11c) are controlled by the particular shape of the end surface (21). A change of the mask to the one as shown by a phantom line (30) allows the shape of the top surface to be changed from the one shown by (21) to the one shown by (31), which allows the degree of the opening of the feed holes (11a), (11b) and (11c) to be desirably controlled.

Abstract: The extrusion head for plastics extruders includes a die head, which is disposed axially in the extrusion direction downstream from a jaw plate. The die head is divided in an at least approximately radial direction into a main part and an orifice part and the cones of the orifice part can be fixed independently of one another at the respectively adjacent cones of the main part and exchanged for other cones in a rapid operation.

Abstract: The present invention provides a die for molding a honeycomb structure, which can be molded without causing bending on a cell grid and which can readily cope with changes of shrinkage percentage of the product. The invention also provides a honeycomb structure, which has no bending on the cell grid and has high strength. The die according to the present invention includes a metal die 1, having a feed hole forming unit 14 provided with feed holes 15 and a slot forming unit 11 provided with slots 12, and a guide ring 2, which has an abutment surface 25 placed face-to-face to a part of the metal die 1 via a clearance sector 22. The slot forming unit includes an outer peripheral slot forming unit 130 and a main-body slot forming unit 160, and there is provided a protruded surface 17 protruded in extruding direction between a main body end surface 16 and an outer peripheral end surface 13.

Abstract: A crosshead die for an extrusion system provides a balanced, even flow of molten material around a circumference. The die has a cylindrical body with opposite first and second ends, an outer wall, a horizontal centerline and a vertical centerline. The die further includes a reduced diameter end portion at the second end thereof. The reduced diameter end portion includes an axial bore. The cylindrical body further has a recessed surface in the first end, and a circular groove in the recessed surface. The groove has an inner edge and an outer edge and the outer edge includes two inwardly curved blending wedges which are positioned in opposed relation on the vertical centerline. The inner edge of the groove merges into a frusto-conical inner wall which tapers axially inwardly and merges with the axial bore in the reduced diameter end portion. The inner edge of the groove has a lesser height than the recessed surface.

Abstract: An improved method is provided for extruding ePTFE tube (12) for use in medical applications. A tube (12) of PTFE is extruded, preferably in an extrusion process, using counter-rotated die components (22, 26). The die component (16) is maintained at a constant temperature during processing. The resulting green tube (12) has enhanced fibrous state formation in a direction perpendicular to the direction of extrusion. The PTFE green tube (12) is then subjected to secondary operations such as stretching and expansion to yield medical product. The ePTFE tube (12) structure is defined by nodes interconnected by elongate fibrils. Both the nodes and fibrils are substantially randomly tilted with respect to the longitudinal axis of the tube (12). This particular structure yields a tube (12) which exhibits a high degree of radial tear strength useful in medical applications.

Abstract: The present invention includes a method and apparatus for extruding viscoelastic polymers. Specifically, the invention is directed to an extrusion die for manufacturing viscoelastic and similar polymers while reducing or eliminating die swell. These polymers typically exhibit Deborah numbers that are in the range of 20 to 30 as compared to 1 to 5 of styrene butadiene, as well as high elasticity or elastic modulus. The method and apparatus can be used to manufacture xerographic toner that has a relatively low melting temperature, which can cause a reduction in the power consumption of a printer or copier, and can increase the life of some of the fuser components contained within the machine. More importantly, use of toner particles created using the present invention can reduce or eliminate the phenomenon known as "vinyl off set," which causes the transfer of a hard copy image onto a vinyl material.

Abstract: The present invention provides a laminated-parison extrusion-molding apparatus which includes a head body; a multi-ring structure having a spider provided in the head body; a head core provided inside the multi-ring structure; an outer cylinder member provided surrounding a lower outer periphery of the multi-ring structure, the outer cylinder member constituting a lower portion of the head body; and an annular member provided inside the outer cylinder member, wherein an outer main material is supplied to a flow passage provided between the outer cylinder member and the annular member so as to achieve an outer main material layer having a uniform thickness.

Abstract: Multiple die components are constructed to provide separate flow paths for multiple layers of extruded plastic until the exit of the die assembly. The multiple layers are then allowed to join at ambient temperature and pressure.

Abstract: An extruder and mandrel assembly is used in a plastic pipe forming apparatus. The mandrel itself is formed from a pair of elongated tubes comprising an inner tube and an outer tube separated from the inner tube by a plastic flow path through the mandrel. The inner tube is formed by a pair of sleeves comprising an inner sleeve and an outer sleeve which is held within the mandrel by the inner sleeve. The inner sleeve is secured at its upstream end to the spider of the extruder head and the outer sleeve is secured by a releasable interlock to the inner sleeve with the releasable interlock being accessible from the downstream end of the mandrel. Therefore, the mandrel does not have to be released from the spider of the extruder head in order to remove the outer sleeve of the inner tube of the mandrel.

Abstract: Large, multi-layer parisons with an inner layer, an intermediate layer, and an outer layer for use in intermittent extrusion blow molding are formed using a die head including a housing, an annular inner conduit having a first resin inlet with a horizontal axis, an intermediate conduit having a second resin inlet with a horizontal axis, and an annular outer conduit having a third resin inlet with a horizontal axis, a closable, tubular extrusion orifice in communication with the inner, intermediate and outer conduits, the first inlet being in a plane above the second inlet and the second inlet being in a plane above the third inlet; and first, second and third reciprocating screw extruders, each extruder including a cylinder with a resin inlet and a resin discharge outlet, a screw rotatable within the cylinder to convey the resin from the resin inlet to the discharge outlet, the screw being axially movable away from the outlet when the screw is rotating, and drive means for moving the screw rapidly toward the

Abstract: An apparatus and method for making a grooved plastic spacer for a slotted core type telecommunications cable includes a helically shaped calibration member inserted into each groove after extrusion of the spacer to maintain the shape of the groove until it is sufficiently cooled. A telecommunications cable made according to the method includes a spacer made of plastic having a melt flow index equal to or greater than 0.65 g/10 min.

Abstract: A method an apparatus for simultaneously dispensing a plurality of viscous materials, such as dentifrice pastes, produces a striped outer layer of a first material surrounding a core of a second viscous material. The apparatus includes a collapsible tube or pump-type dispenser containing a first viscous material and a second viscous material of a contrasting color in contact with the first material so that both materials are dispensed simultaneously. The tube or dispenser includes an outlet nozzle having a shaped outlet capable of scraping and removing a portion of the outer layer of viscous material to dispense the core material having stripes of the outer material. The nozzle is capable of forming a plurality of fine pin stripes on the core material.

Abstract: An extrusion head includes a first housing member and second housing member each with a passageway extending therethrough, the two housing members being attached to each other such that the respective passageways are aligned. The first housing member includes structure positioned within the passageway for applying a coating material (such as PVC) to a wire as it is drawn therethrough. The second housing member includes an inlet channel adapted to be attached to a source of nylon, the inlet channel extending to a recessed groove in the end of the second housing member, which end is adjacent to the first housing member, such groove surrounding a surface configured to form a spacing between the two housing members through which spacing the nylon passes in a direction toward the wire as it is drawn therethrough.

Abstract: A co-extrusion method for making a blown-film textured liner having a textured surface to provide improved soil gripping properties and smooth untextured edges for improving the integrity of the joint between adjacent liner sheets.

Abstract: A novel die member for positioning in a uniformly tapering, frustoconical portion of a through bore in a body member of co-extrusion, cross-head coating apparatus. The die member has an external surface with a first, frustoconical portion dimensioned for mating engagement with the body member bore extending from the front end of the die member and tapering outwardly to terminate in a plane parallel to and intermediate of the planes of the front and rear ends of the member. A second, cylindrical, external surface portion, of smaller diameter than the adjacent, larger end of the first surface portion, extends to the rear end of the die member. An annular groove of substantially semi-circular cross section extends into and 360.degree. about the second surface portion rearwardly adjacent the first surface portion.

Abstract: An extrusion die has a cylindrical body with an outer cylindrical wall, opposite first and second end walls, an axial bore extending therethrough, and bores for mounting the die to the extrusion system. The cylindrical body includes a flow inlet on the outer wall and first and second symmetrical flow channels which extend into the body from the flow inlet and terminate at a pair of opposite openings formed in the second end wall. A tapered end portion is in a concentric fashion with the cylindrical body. The end portion has a circumferential groove formed therein adjacent the juncture of the end portion and the cylindrical body wherein the pair of opposite openings are in fluid communication with the groove. A mating head has a body portion with a bore formed therein with an inner surface tapered to mate with the end portion of the die.

Abstract: The tubular extrusion of a thermoplastic nonderivatized cellulose solution about a mandrel and through a long air gap in excess of 304 mm is facilitated by use of a mandrel which is extensible from the extrusion die. On extrusion start-up, the mandrel extends a short length from the die. For steady-state operation, the mandrel is extended its full length from the die. Also disclosed is a mandrel structure to facilitate the introduction of a nonsolvent liquid into the interior of the extruded tube at a high location on start-up of extrusion and at a lower location during steady-state operation.

Abstract: The present invention provides a blow spinning die particularly suited for spinning solvated pitch into fibers having a random cross-sectional structure. Additionally, the present invention provides a process for blow spinning fibers from solvated pitches. The present invention also provides pitch fibers having a high energy internal molecular structure. Finally, the present invention provides carbon fibers which have a non-radial internal structure.

Abstract: A coextrusion die includes a plurality of thin annular disks stacked on top of each other. Each annular disk includes a plurality of openings aligned with openings in the adjacent disk, thus forming multiple streams. Plastic melt may be supplied to the die coplanarly. Stacks of annular disks may be used to form modules through which plastic melt can be axially directed.

Abstract: 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.