Abstract: A mold equipped with a core having a plurality of branching columnar distal portions in the extrusion direction and a die having an aperture surrounding the distal portions. A softened flexible resin is injected from one end of a resin flow path formed between the core and the die and extruded in order to form a pipe material having a plurality of circular liquid flow paths which are mutually independent and have the same inner diameter. The distal portions of the core shaped as a row of circular distal portions aligned on the same axis, where the two edge distal portions have a smaller diameter than the distal portions disposed between the edge distal portions, while the portions of the aperture surrounding each of the distal portions have the same diameter.

Abstract: A honeycomb structure body molding die is disclosed including a die main body, having a feed bore section and a slit recess section, and a guide ring having an upright support section and a guide section carried on the upright section, which includes a stepped section and has a central slit recess forming section, provided on the stepped section, and an outer circumferential slit recess forming surface. The die main body has a non-opposing region, formed on an area outside the stepped section, in which the outer circumferential slit recess forming surface does not axially face the guide section, while having a feed bore closing region closing the feed bores. The die main body has outer circumferential-skin forming material feed passages formed in an area outside the feed bore closing region for feeding the molding material to a squeezing outlet for forming an outer circumferential skin.

Abstract: Extruding radiused plastic articles with an extruding machine terminating in die defining a path of travel between upstream and downstream ends. The die has an outlet opening extending longitudinally in the direction of the path of travel, the opening oriented so a polymeric material is extruded therefrom in a direction approximately perpendicular to the path of travel through the die. Oppositely rotating rollers of tapered diameters are disposed side by side to receive the extrudate therebetween, the rollers arranged so their longitudinal axes intersect and their smaller diameters are oriented towards the downstream end of the die. Extrudate passing through the opening is characterized by a higher flow rate proximate the upstream end thereof to thereby form a radiused extrusion. The rollers draw the extrudate from the die outlet opening without significantly altering the radiused shape of the fluid plastic material.

Abstract: In a twin-screw extruder including a barrel, which has two screws disposed in parallel in its inside and an opening at one edge, and an extrusion molding die disposed to the opening side of the barrel through a straightening vane and a filter net, the straightening vane includes a first straightening vane and a second straightening vane, the first one has a hole forming region having plural through holes formed in a region whose size and shape are in agreement with the size and the shape of the inner periphery of the opening portion, and the second one has a hole structure whose size and shape of its inner periphery at one opening edge are in agreement with the size and the shape of the hole forming region, and its sectional area is reduced once in a process to the other opening edge and then expanded in a taper shape.

Abstract: A spider for an extrusion apparatus located upstream from a die, through which a profile is extruded. The spider can have an outer housing with a central flow passage therethrough. An inner hub can be positioned within the central passage for supporting an inner portion of the die. At least one spider leg can be secured to the outer housing and the inner hub, and support the inner hub within the central passage. The at least one spider leg can recess radially rearwardly outwardly in the downstream direction such that molten polymer flowing through the central passage flows around the at least one spider leg, separating and rejoining together earlier in inner radial regions close to the inner hub than in outer radial regions close to the outer housing for reducing spider lines on inside surfaces of extruded profiles.

Abstract: An extrusion molding system includes a die having a first opening with a unvariable shape and a second opening with a variable shape, an extruder which feeds resin to the die, and a gear pump arranged between the die and the extruder. An ECU conducts a first sequence control to change the shape of the second opening and a second sequence control to change the rotation speed of the first gear pump in synchronism with a change in the shape of the second opening.

Abstract: A die for forming a honeycomb structure may realize a sophisticated formability and superior resistance to wear. The die may be provided with a die base including two surfaces, one being provided with slits of honeycomb shape, and the other being provided with back holes through which a forming material may be introduced. The die base may include: a die precursor obtained by stacking and bonding a first member (one surface of the die base) and of tungsten carbide-based super hard alloy and a second member (the other surface of the die base) and of a metal material that causes at least up to three phase transformation of martensite transformation, bainite transformation, and pearlite transformation by cooling of an austenite phase together. Tensile and compressive stresses in a mutually bonded surface of the two plate-like members are 1000 MPa or less.

Abstract: A catheter molding apparatus that includes a fore-stage extrusion molding device for extrusion molding an inner layer tube of resin so as to fit a core wire material of metal therein, a braided layer attaching unit for attaching a braided layer made by the braiding of a reinforcing thread to the outer surface of the inner layer tube molded by the fore-stage extrusion molding device and once cooled, thereby molding a braided tube. The apparatus also includes a post-stage extrusion molding device for extrusion molding a raw material tube for a catheter by fitting an outer layer tube of resin thereon, and a take-off unit for taking off the raw material tube. The fore-stage extrusion molding device, braided layer attaching unit, post-stage extrusion molding device, and take-off unit are continuously disposed along the longitudinal direction of the tubes.

Abstract: An extrusion die for extruding hollow profiles is suggested having a die head (2), which is connected to a runner part (1) and forms extrusion channels (3) for shaping a profiled strand (4), and having a runner chamber (5), which is provided between the die head (2) and the runner part (1) and runs transversely to the extrusion channels (3), which is connected around its circumference (8) to an annular channel (7) for impingement with plastic melt and from which the extrusion channels (3) of the die head (2) originate. In order to provide advantageous construction conditions, it is suggested that the runner part (1) have an inner channel (9) discharging into the runner chamber (5) inside the annular channel (7) for additional impingement of the runner chamber (5) with plastic melt.

Abstract: An extrusion apparatus is used for extruding material through a nozzle (10) for forming a product In the nozzle (10), the material is pressed around rods (9) so that tubular cavities (13) are formed in the wall of the product. The rods (9) are hollow and the apparatus comprises channels (14) connected to the hollow rods (9) to enable flow in the tubular cavities (13).

Abstract: An apparatus and method for molding balloon catheters is disclosed. The balloon may be molded by providing a polymeric tube within a mold having an interior cavity in the shape of the desired balloon. Microwave energy, which may be generated by a gyrotron, may then be directed toward the mold, to heat the polymeric material without heating the mold. Once heated, pressurized fluid may be injected into the tube to blow the polymeric material against the interior cavity whereupon the material can cool to form the balloon or can be further heatset by additional microwave energy and be cooled to form the balloon. In accordance with one embodiment, microwave energy can also be used without a mold to form a medical device. A polymer extrusion apparatus is disclosed utilizing a microwave energy for heating polymer feedstock material within the extruder tip and die unit just prior to formation of the extrudate product.

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 an exit section of the drawing die to form a hollow hole-forming pattern. The forming jig can easily and inexpensively design or change the design of a forming pattern of hollow holes and the external configuration of a formed body, and can form fine hollow holes at a high density.

Abstract: There is disclosed a die 1 for forming a honeycomb structure comprises: a plate-like die substrate 2 having at least two surfaces 8, 9, in which back holes 3 for introducing a green material are formed in one surface 8, and slits 4 communicating with back holes 3 are formed in the other surface 9; an underlayer 5 disposed on the substrate 2 so as to coat at least a part of a portion constituting the back hole 3 and the slit 4; an intermediate layer 6 disposed so as to coat at least a part of the underlayer 5 and constituted of tungsten carbide particles whose average particle diameter is 5 ?m or less and containing W3C as a main component; and a surface layer 7 disposed so as to coat at least a part of the intermediate layer 6 and constituted of diamond and/or diamond-like carbon.

Abstract: A method for producing a molded product consisting of a resin polymerized by a melt polycondensation reaction, comprising continuous feeding of a prepolymer in molten state from a prepolymer feeding port to a polymerization reactor, discharging from holes of a porous plate, followed by polymerization while dropping along a supporting substrate under reduced pressure, and molding by transferring to at least one molding machine in molten state without solidification, wherein transfer pressure to said molding machine is controlled so as to maintain at an arbitrary pressure from 0.1 to 100 MPa (absolute pressure).

Abstract: A die head for an extruder including an outer shell, an inner cylindrical mandrel, an annular die gap at a discharge side of the die head, at least one intake opening for receiving a melted mass, at least one distribution element for distributing the melted mass to a central ring channel terminating in the die gap, an inflow channel connecting the at least one intake opening to the at least one distribution element. Further, at least one of the distribution element and the inflow channel are formed such that the distribution element is set into torsional motion around a longitudinal axis of the mandrel due to an flow of the melted mass, and the flow of melted mass is routed to the central ring channel.

Abstract: An extrusion die for forming polymeric foam sheets includes a first die body, a second die body, and a manifold within the first die body and the second die body, wherein the manifold includes an inlet to receive polymeric material. The extrusion die further includes a die exit formed by opposing die lips in fluid communication with the manifold and a temperature control zone adjacent the die lips. The extrusion die further includes two generally planar shaping surfaces in proximity to the die exit and place one above and one below the die exit. Adjustable shoes are disposed in proximity to the die exit on each side of the die exit and between the planar shaping surfaces.

Abstract: The invention discloses an improved die assembly for the extrusion of thermoplastic resin cellulosic fiber composite profiles meant to minimize and substantially prevent the occurrence of melt fracture on the surface of the extruded composite profiles. Comprising the die assembly are a balanced flow passage having a heated compression zone, a heated transition zone, a heated converging die zone, a die land, which corresponds to at least a portion of the downstream end of the flow passage and is cooled to temperature below the melting point temperature of the thermoplastic resin. The invention also discloses a production process for composite profiles which includes the steps of providing resin and fiber, producing a composite compound, processing the compound through an extrusion system, extruding the compound through the die assembly to form the desired profile, cooling the profile and cutting it to length. Also disclosed are products produced by the production process.

Abstract: Disclosed is a die (10) for forming a honeycomb body having a structure provided with groovy slits (2) on a front face thereof, the slits being formed by cell blocks (3) and back holes (4) on a back surface thereof, each hole being communicatively connected with the slit. The number N of the cell blocks per one side of the die is even number. According to the die for forming the honeycomb body, strain generated on an extruded face of the honeycomb body after extrusion and bending of the honeycomb body can be reduced as well as the die can maintain a stable frictional force of extrusion and is excellent in extrudability and wear resistance.

Abstract: A method for forming honeycomb structures, such as wall-flow honeycomb filters, which utilizes extrusion of multiple material supplies at once. Such methods may be used to form intermittent plugs or other structures in the cell channels during the extrusion process, for example. A die assembly is provided which includes secondary feedholes machined in the pins for intermittently or periodically injecting secondary material (e.g., plug material) into the cell channels of the honeycomb structure while it is being extruded.

Abstract: Equipment (1) used in the molding or plastic pipe includes die tooling (3) provided with a plastic flow distributor (25) at the upper end of the die tooling. The plastic flow distributor has adjustable flow to provide an even distribution of plastic from an extruder into at least one die passage (9) within the die tooling.

Abstract: A device for manufacturing a double-walled thermoplastic pipe with a connecting sleeve has a molding tunnel with a succession of molds for forming a corrugated molding wall and a connecting sleeve, respectively. An extrusion device extrudes a first flexible tube into said molding tunnel and a second flexible tube into said first flexible tube. A first gas channel is arranged for generating a pressure between said first and second flexible tubes. A compressed-gas control device is connected to said first gas channel for generating a pressure p1 or a pressure p2 in said space between said first and second flexible tubes by compressed air emerging from said first gas channel. A second compressed-gas control device is connected to a second gas channel for guiding compressed gas onto an inner side of said second flexible tube. Said first pressure controller is connected to said first gas channel via a compressed-gas line that is connected to an additional compressed-gas reservoir for gas exchange therewith.

Abstract: The invention relates to a method for extrusion, in particular for the production of bent extruded products, in which the extruded product (8) is formed in a die mounted before a support yoke (2) of an extrusion machine and then bent or curved by means of the effects of an external force, whereby at least one bending radius is formed, within the support yoke, on the extruded product (8) which enters the support yoke (2) with a straight extrusion direction (4). An extrusion unit further comprises a support yoke (2) formed with a lateral yoke opening (3), running transverse to the straight extrusion direction (4).

Abstract: This invention relates to the preparation of a multi-layered rubber composite, said composite and a tire having a component prepared thereby. The multi-layered rubber composite is composed of at least two individual rubber compositions configured as at least three parallel aligned alternating rubber layers, wherein each rubber layer extends through the rubber composite thickness from one side to the other opposing side. The multi-layered rubber composite is prepared by co-extruding at least two individual rubber compositions, via an individual extruder for each rubber composition, to an internal cavity of a former. Said former is comprised of an internal cavity which contains a sequence of flow deflectors and channels for guiding the at least two individual rubber compositions to form said multi-layered rubber composite in a single manufacturing step.

Abstract: An apparatus for making wedged plate has an extruder to provide melted plastic material. A die head has a channel with an inlet and an outlet. The inlet of the die head is connected to an outlet of the extruder. The outlet of the die head has a thick side and a narrow side. A rolling device has two rollers and a space between the rollers. The space has a thick portion and a narrow portion at opposite sides. The space of the rolling device is aligned with the outlet of the die head, so that the plastic material flows into the space of the rolling device via the die head and is rolled by the rollers. A cutting device is arranged behind the rolling device to cut the rolled plastic material to get wedged plates.

Abstract: The invention relates to a moulding system (3), in particular a calibration die (17), for an extrusion plant, with preferably parallel inlet and outlet faces (28, 29) spaced at a distance apart and with side faces (30, 31, 32, 33) extending between them. A longitudinal axis for the object to be fed through a calibration orifice (24) is disposed substantially perpendicular to the inlet and outlet face (28, 29). Provided between a shaping surface (25, 26) and a side face (30, 31, 32, 33) is a gap (37, 38) extending at least across a part of the distance between the inlet and outlet face (28, 29). The gap (37, 38) is disposed between several immediately adjacent parts of several shaping surfaces (26) of the calibration orifice (24) and at least one of the side faces (30, 31, 32, 33). At least the parts of the shaping surfaces (26) co-operating with the gap (37, 38) are displaceable relative to the other shaping surfaces (25).

Abstract: A polymer extrusion head for forming continuous shapes having one or more lumens therein. The head includes an extrusion mandrel and die. At least one lumen pipe is disposed radially through a port in the die to intersect the polymer flow in the annular region between the tip and the die. The lumen pipe is a welded assembly having a 90° turn formed as a mitered joint with zero bend radius. The lumen pipe is held in a pin vise engaged in the die such that position of the lumen pipe may be readily adjusted. Axial and radial positions are established during assembly by means of a gauge block. A plurality of lumen pipes may be accommodated for a plurality of lumens by a manifold distribution system including individual lumen pipe assemblies.

Abstract: An extrusion die for extrusion molding of a honeycomb structure has back holes for introducing a raw material to be molded and slits for extruding the raw material. The extrusion die comprises an inside section, an outer peripheral section, and an outermost peripheral section; the width of the slit 14 disposed in the outer peripheral section is wider than the width of the slit disposed in the inside section; and when the surface roughness (Ra) of the slits in the inside section and the outer peripheral section is 0.1 ?m or smaller, or when the surface roughness (Ra) of the slits in the inside section and the outer peripheral section exceeds 0.1 ?m, the relationship between the surface roughness a of slit in the inside section and the surface roughness b of slit in the outer peripheral section satisfies the condition that 0.1<a/b<10.

Abstract: A method and apparatus for extruding a corrugation-free polystyrene foam with 100% carbon dioxide as the blowing agent by extruding the extrudate through an annular die opening so that it contacts a choke ring inner surface. A foam made with the apparatus according to the invention will have no visible corrugations and an average cell size of less than 0.35 mm.

Abstract: A spiral die assembly can obtain a homogeneous pipe body, an inflation film with/without drawing and a functional film by dispersing molten resin homogeneously, and the spiral die assembly is capable of being applied to various molten resins and extruding conditions. The spiral die assembly comprises a main body 1 of said spiral die assembly, a mandrel 2 having a spiral groove 3 around its outer surface inserted on the inside of the main body and a rotatable ring 5 having a desired width fitted along the outer surface of the spiral groove 3 and fitted in a portion of a die cylinder which forms the inner surface of the main body 1 in a range corresponding to both ends of the spiral groove 3.

Abstract: In a die for molding a honeycomb structure, in which a coating layer is formed on a die base so that slits with a particular width are provided, the slits are provided so as to have a width of 30 to 200 ?m by forming the coating layer by a substrate layer with a thickness of 10 to 100 ?m and a surface layer with a thickness of 1 to 30 ?m. Further, the substrate layer is formed by a metal layer containing no oxide. A thin-wall honeycomb structure with a wall thickness of 30 to 200 ?m can be formed, and moreover a die for molding a honeycomb structure, in which the coating layer is not damaged and thus the durability is high, and a manufacturing method thereof can be provided.

Abstract: Pipe molding apparatus having a moving mold tunnel includes an upstream and at least one downstream mold block. Each mold block comprises mold block sections which close with one another to form the pipe and which open relative to one another to release the pipe. The mold blocks move downstream of the apparatus together with one another when forming the pipe and move upstream separately from one another when releasing the pipe which cools and shrinks in both diameter and length in the mold tunnel. Each mold block has a hollow pipe forming region with the pipe forming region of the downstream mold block being decreased in both diameter and length relative to the pipe forming region of the upstream mold block to compensate for the plastic shrinkage.

Abstract: An extrusion molding apparatus comprises a shaping die for producing a ceramic molded product, and a screw extruder having built therein an extruding screw (40) for mixing while leading a ceramic material forward. The extruding screw (40) includes a pressing screw portion (410) having a first lead (411) and a dispersing screw portion (420) having a second lead (421) adjacent to a forward end (412) of the pressing screw portion (410). The second lead (421) is formed in such a manner that the rear ends of all the second lead surfaces (426) at the rear end (422) of the dispersing screw portion (420) and the forward end of the first lead surface (416) at the forward end (412) of the pressing screw portion (410) are displaced from each other.

Abstract: The extruding apparatus has the molding die to form the ceramic molding, the screw extruder containing the extrusion screw to knead and guide the ceramic material toward the molding die. The extrusion screw is comprised of the pressure screw part and the diffusion screw part. The diffusion screw part provided at the front end of the extrusion screw has a diameter greater than the screw diameter of the pressure screw part.

Abstract: An annular co-extrusion die for extruding multi-layer tubular plastic film has inner die members stacked one upon another and having radially outwardly extending surfaces forming radially outwardly extending helical passages between respective pairs of inner die members. An annular outer die member surrounds the stacked inner die members and forms a longitudinally extending annular passage therebetween for conveying plastic material from the radially outwardly extending helical passages to an annular extrusion orifice. A lower inner die member has a first feed passage extending from a lower surface thereof to a substantially horizontal upper surface thereof at a position spaced from a central longitudinal axis of the longitudinally extending annular passage, the substantially horizontal upper surface having a first groove extending from the upper end of the first feed passage to the longitudinal axis.

Abstract: A die for extrusion molding of a honeycomb which comprises a structure provided with a groovy slit (2) formed by cell blocks (3) on a front face thereof, and additionally provided with a puddle inlet, on a back face thereof, communicatively connected with the slit (2), wherein each cell block (3) has a soft film (16) on a hard film (14) formed on outermost surfaces of the slit (2) and puddle inlet fabricated in a cell-block body (10). According to the die for extrusion molding of a honeycomb, a dimensional error of the die is possible to be eliminated, a stable force of extrusion friction is possible to be maintained, both extrusion moldability and abrasion resistance are possible to be excellent, and additionally an adjustment of the die at the time of extrusion molding can be performed easily.

Abstract: The manufacturing apparatus of a resin molded product has a feed block that sets a layer configuration of the resin molded product obtained by molding a plurality of molten resins. The feed block includes a feed block body having a through hole, and a plurality of replacement blocks that are removably fitted into the through hole and have layer configuring passages corresponding to different layer configurations. A replacement block before change is pushed out of the through hole by a replacement block having a layer configuring passage corresponding to a layer configuration after change, thereby changing the layer configuration. This allows an easy change of a layer configuration, and in particular, prevents degradation of resin due to heat or oxidation, and reduces time for the change and a material loss even when a significant change of the layer configuration such as a change of a layer arrangement is performed.

Abstract: An mandrel for extrusion of hollow bodies, such as, polyvinyl chloride (PVC) hard, compact, and foamed pipes, includes an inner collar and an outer collar, and webs radially joining the inner collar and outer collar. The webs can be arranged twisted and/or offset in radial direction.

Abstract: An apparatus for making reinforcement ply material wherein reinforcement elements are grouped in untwisted sets and adjacent reinforcement elements in the same set are spaced apart a distance less than the distance between adjacent sets. The apparatus includes an extruder and a die head into which the extruder extrudes an elastomeric material. The die head defines a die throat and includes a guide insert which guides the reinforcement elements into the die throat. The guide insert has passages through which the reinforcement elements pass and which are arranged in a pattern corresponding to the arrangement of the reinforcement elements in the reinforced ply material.

Abstract: Polymer processing systems are provided including an extrusion assembly, a specially configured decompression chamber assembly, and a die assembly. Such systems are effective to provide shaped polymer products having reduced extrusion markings.

Abstract: An apparatus for producing seamless plastic tubes comprises an injection head to which molten plastic material is fed by an extrusion device. The injection head has a plate-shaped distribution device 13a, 13b having an intake opening 20 into which the feed passage 17a, 17b for the molten plastic material opens. In the distribution device, distribution passages 14 extend in a star configuration from the intake opening 20 and extend perpendicularly to the axis of the injection head, wherein each distribution passage 14 has a straight radial passage portion 14r and three branch passages 14z which branch therefrom and which each go into arcuate passage portions 14k which, in the region of the periphery of the distribution device, communicate with the annular gap 25 of the injection head, with the adjacent ends at a respectively identical angular spacing, and they each introduce a respectively identical volume flow into the annular gap 25.

Abstract: An extrusion system for extruding a layer of a plastic or rubber material onto a work piece without having to continuously adjust the extrusion system during the “set-up” mode to “full-run” mode, wherein the extruded layer exhibits a predetermined cross-section size and a uniform wall gauge concentricity.

Abstract: The invention concerns a process and apparatus for the coextrusion of rubber mixtures, comprising a main extruder (1) with an extrusion head (10) having at least two flow channels (14, 15), each for a rubber mixture (A, B), the channels opening into an extrusion orifice (18) through which the two rubber mixtures (A, B) are propelled. The extrusion orifice (18) is delimited by a first wall (111) and a second wall (161). The apparatus also comprises at least one micro-extruder (2) for a third rubber mixture (C), whose extrusion head (22) is provided at its end with a nozzle (23) passing through the two flow channels (14, 15) such that the third rubber mixture (C) is inserted into each rubber mixture (A, B) upstream from the extrusion orifice (18).

Abstract: Extruded honeycomb products are formed by means of an extrusion die incorporating a pin support section positioned between the die body and the pin array forming the die discharge slots, the pin support providing enlarged support segments that improve pin stability and die resistance to pin damage without overly restricting batch flow through the die.

Abstract: An apparatus and method to adjust the dimensions of thermoplastic components following passage of the component through final processing in a fixture. The invention particularly relates to an apparatus for maintaining product tolerances on thermoplastic components that have undergone post-form extrusion. In addition, the invention relates to a method for maintaining product tolerances on post-form extruded thermoplastic materials.

Abstract: A tire having a tread composed of two non-conductive layers, each layer containing a circumferential insert of conductive mix, the inserts having a wider interface at the interface of the two layers. An apparatus for extruding a layer, provided with a conductive insert, including a main extruder for extruding a non-vulcanized, non-conductive layer, and a micro-extruder having an extrusion head, provided at its end with a nozzle, for extruding a conductive insert in the layer.

Abstract: The present invention is the apparatus and method for producing a plastic sheet having a pattern produced in a layer therein. The plastic sheet is a single layer sheet or a multi-layer sheet. The pattern is produced by mixing two or more plastic extrudants together in a mixer. The pattern is visible in the layer containing the two or more plastic extrudants because an at least one of the plastic extrudants is at least partially transparent. The mixer used to produce the pattern includes a housing having an end configured to expel the mixture of the two or more extrudants through a plurality of outlets. The mixer further comprises a rotatable shaft and at least one projection coupled to the shaft and rotatable with the shaft, the at least one projection configured to orient the mixture of the two or more extrudants relative to the plurality of outlets in the housing. The mixer further comprising a thrust bearing configured to couple an end of the shaft to the housing.

Abstract: A blown film die divides a flow of material into two flows with higher and lower flow portions and recombines the flow by combining higher flow portions with lower flow portions. The flow can be divided in circumferential channels between an annular feed ring and an annular distribution ring.

Abstract: An extruder apparatus and method for producing an extruded tubing having varying inner dimensions without changing the outer dimensions. The tubing is forced from the die face of an extrusion head having an extruder die and an internal mandrel determining the outer and inner dimensions, respectively, of the extruded tubing. The outer dimensions of the mandrel varied by the user to change the inner dimensions of the extruded tubing. A pressure is maintained in the extruded tubing to prevent its collapse and that pressure is changed based upon the change of the external dimensions of the mandrel and the wall thickness of the tubing. In one embodiment, the mandrel is comprised of a core and a plurality of telescoping sleeves. Each sleeve is movable between a retracted position where the sleeve is displaced away from the die face and an extended position where sleeve is at the die face. There may be multiple mandrels in the case of multi-lumen catheters.

Abstract: The present invention provides a device for producing an unvulcanized rubber member for tire manufacturing. The device includes an extruder with a die that extrudes the unvulcanized rubber member to form multiple rib-protrusions that extend in a direction corresponding to a circumferential direction of the tire. A conveying apparatus receives the unvulcanized rubber member and conveys it in the extrusion direction. A roller has an outer surface with protruding portions that form multiple grooves in the unvulcanized rubber member that extend in a direction radial direction of the tire and intersect the rib-protrusions.

Abstract: The invention concerns a continuous manufacturing method which consists in producing a blank (E) by extrusion, bringing said blank to a temperature for molecular orientation, passing said blank around a radial expansion mandrel (12); gauging and cooling while subjecting the blank to axial traction. The radial expansion produced on the mandrel (12) is partial so that the internal diameter (B) of the blank (E), when it leaves the mandrel, is less than the nominal internal diameter (D) of the finished tube; performing an additional radial expansion of the blank, up to its nominal diameter, by internal fluid pressure. In permanent operating conditions, the inner surface of the blank (E) is no longer in contact with the mandrel (12).