Abstract: An extrusion die has a plurality of die layers stacked one upon the other in a direction generally parallel to the central axis. Each of the layers has an annular flow distribution ring having an outer generally cylindrical surface and an annular feed ring surrounding and engaging the outer surface of the distribution ring. At the engaged surfaces of the feed and distribution ring, the flow from the feed ring is divided into a number of substantially equal flow portions. Seals between adjacent engaged surfaces confine the flow to between the circumferential surfaces of the feed and distribution ring. Half of the flow portions are directed to a recombination region on one side of the distribution ring, and half are directed to a recombination region on the other side of the ring. In recombining, weld lines are formed in high flow areas to minimize the deleterious effect of polymer degradation.

Abstract: Broad parts are formed on at least one passage including a passage for forming the thinnest layer among passages for respective resin layers of a multilayer sheet at an upstream side of a confluence. In the broad parts, clearances become larger to both ends of the passage along the width thereof.

Abstract: An apparatus and method for spinning bicomponent sheath/core filaments such that the filaments are uniformly quenched. The apparatus includes a distributor plate, and spinneret and a shim position between the distributor plate and the spinneret. The spinneret includes a plurality of holes positioned so that the density of holes is the lowest near the center of the spinneret and increases as radially proceed outward. More specifically, the holes are substantially configured in the shape of a parallelogram in which the sides of the parallelogram are all of equal length. Additionally, the shape of the parallelogram is more flatten the further the parallelogram pattern is located from the center of the spinneret. In this manner of positioning the holes, filaments therefrom do not significantly impede quench air from uniformly reaching filaments in the outer rows.

Abstract: A method and apparatus for extruding unvulcanized rubber in a tire production process, in which an unvulcanized rubber extruded member can be formed by extrusion. An extruded rubber member having a cross section in which a portion of a second unvulcanized rubber intrudes between portions of a first unvulcanized rubber is formed by extrusion. The apparatus includes a first passage for the first unvulcanized rubber, a second passage for the second unvulcanized rubber, and a flow dividing mechanism where the first and second passages are adjacent or connected, which separates a portion of the first unvulcanized rubber passing through the first passage such that the first unvulcanized rubber is disposed at both sides of the intruded second unvulcanized rubber. In the method, the first unvulcanized rubber is divided into two flows, and a portion of the second unvulcanized rubber is caused to intrude therebetween.

Abstract: A method and apparatus for extruding plastic products having large cross sections, which require a correspondingly large die cross section, is described in which the cross section of the die is divided into regions of predetermined flow and separate flow streams are supplied to each region in proportion to the relative size of the flow region to the overall die cross section.

Abstract: A melt distribution block for feeding melt through an extrusion die to an extrusion passage. The melt distribution block has a generally annular body with inner, outer, front and rear faces. The front and rear faces include a series of flow divider channels therein extending generally radially inwardly from an inlet and terminating in a plurality of feed spirals. The feed spirals curve radially inwardly from the flow divider channels to encircle the inner face and narrow toward a radially inwardly disposed end. The feed spirals on the front and rear spaces curve in respectively opposite directions. An inlet port extends into the outer face and fluidly communicates with the inlet of the flow divider channels. A melt distribution die includes an axially stacked array of melt distribution blocks interspersed with separator blocks extending radially about a centrally disposed mandrel to define an extrusion and passage therebetween.

Abstract: A method for making a composite extrusion die for making a cellular honeycomb structure with thin cell walls. The method includes the steps of drilling a grid of separate feed holes/channels into an inlet face of an extrusion die base element, and cutting a grid of intersecting primary outlet slots into an outlet face of the base element, where every alternate one of the primary outlet slots is in direct communication with a plurality of the feed channels. Further, the method includes cutting a grid of intersecting secondary outlet slots into the outlet face, where each one of the secondary outlet slots bisects each one of the primary outlet slots. The method further includes scoring a plurality of indentations into that region of the outlet face that does not contain any of the primary and secondary outlet slots, and filling each of the feed channels and each of the primary and secondary outlet slots with a filler material.

Abstract: The invention is related to the formation of three different and repeated stripes abbreviate as ABCABC-typed or A_B_C-typed at the die exit. The symbol, “_”, implies that there is no coating between two adjacent stripes. In this invention a guide shim and a guide die are inserted between two coating dies. Three different coating solutions will flow into the die assembly through different inlet positions. Two of which are introduced from the two coating dies will flow through the multiple channels provided in the guide shim and the guide die respectively and then contact with each other and with the third solution introduced from a side of the guide die in the same slot section to form the ABCABC-typed stripes. The coating solutions can also flow through the multiple channels to the same slot section but not contact each other to form the A_B_C-typed stripes at the die exit with a modification of the die assembly.

Abstract: A method of extruding plastic material in multi-layer form includes: providing an extrusion die having a first body member and a second body member surrounding the first body member and forming an annular passage therebetween which communicates with an annular extrusion orifice, the body members having a series of helical grooves extending around the die and each commencing at a separate location, the separate locations being spaced around a lower portion of the first body member. A single encapsulating unit provides a flow of encapsulated plastic material comprising a first plastic material surrounded by a second plastic material at an outlet thereof. The first body member having a series of cross-holes extending from the encapsulating unit output and each communicating with a respective separate location.

Abstract: A device for extruding multilayer plastic films, boards or tubes with a feed block, whose inputs are fed with polymer melts and which conveys the polymer melts from its inputs via individual layer channels to a slotted passage, forming its output. Temperature control units are arranged spaced part in the feed block along a width of to the individual layer channels for the purpose of heating or cooling.

Abstract: An extrusion apparatus which simplifies changing the relative order of layers of a coextruded laminate, is provided. Advantageously, the apparatus includes an interchangeably disposed, layer sequence selecting device which can be changed out without disassembly of other extrusion apparatus.

Abstract: This invention provides an apparatus and method for injecting an additive directly into a polymer melt stream. The method comprises supplying a melt flow of a polymeric host material to a die assembly having a thin-plate assembly and injecting at least one additive into at least one predetermined location in a cross-section of the melt flow of the polymeric host material while the melt flow passes through the die assembly. The method achieves uniform dosing of the one or more additives in the extrusion direction in the polymeric host material without homogeneously mixing the one or more additives and the polymeric host material. The apparatus for directly injecting one or more additives into a polymer melt stream comprises a pumping system, a die assembly having a thin-plate assembly, and a distribution line.

Abstract: The invention relates to a method and an apparatus for manufacturing an extruded plastic product, the apparatus comprising at least one rotor (1) and at least one stator (2, 3) 4 with a feed gap (4) provided between them, a groove (7) being situated on the other side of the feed gap (4), the groove pressing the material to be extruded out of the apparatus when the rotor (1) is rotated. The cross section of the groove (7) remains substantially unchanged. At the opposite side of the feed gap (4) there is positioned a countergroove (8) in such a way that a processing cavity consisting of the grooves (7), the countergrooves (8) and the clearance between 6 them decreases at least partially continuously along 5 the axis of the extruder. The deformation energy of the material can thus be kept as small as possible due to the unchanging cross section of the groove (7), and the material stays in the groove (7) due to the placement of the flights (7a, 8a).

Abstract: A decorative food formed of a plurality of kinds of fluid food materials and manufactured by using a mold is provided. The decorative food has an outside shape thereof conforming to an interior surface of the mold inclusive of an opening of said mold. The decorative food has a colored pattern divided into multiple divisions extending up to a central portion of the decorative food, in a direction to extrude the food materials into the mold, the colored pattern being formed such that the multiple divisions are arranged with substantially the same ratio at any of a cross sectional area intersecting the direction to extrude the food materials, and wherein the decorative food contains therein a foodstuff. Also disclosed are an apparatus and method for manufacturing the decorative food.

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: A melt distribution block for feeding melt through an extrusion die to an extrusion passage. The melt distribution block has a generally annular body with inner, outer, front and rear faces. The front and rear faces include a series of flow divider channels therein extending generally radially inwardly from an inlet and terminating in a plurality of feed spirals. The feed spirals curve radially inwardly from the flow divider channels to encircle the inner face and narrow toward a radially inwardly disposed end. The feed spirals on the front and rear spaces curve in respectively opposite directions. An inlet port extends into the outer face and fluidly communicates with the inlet of the flow divider channels. A melt distribution die includes an axially stacked array of melt distribution blocks interspersed with separator blocks extending radially about a centrally disposed mandrel to define an extrusion and passage therebetween.

Abstract: An extrusion die apparatus for extruding a multiple layer tubular product comprising an elongated cylindrical mandrel and a plurality of annular die elements mounted co-axially one behind the other on the mandrel forming contiguous annular thickness control passages between the die elements and the mandrel. The die elements have inner and outer conical surfaces inclined rearwardly at a predetermined angle with respect to the longitudinal axis of the mandrel. The die elements are nested together with the outer conical surfaces of one die element facing the inner conical surfaces of an adjacent die element. The inner and outer conical surfaces form conical passages therebetween which communicate with the annular thickness control passages and a helical groove is provided on the outer conical surface of each die element.

Abstract: A pneumatic tire includes a low conductive rubber portion forming at least a cap rubber portion of the tread rubber which provides a tread surface of the tire. A narrow high conductive rubber strip extends in a radial direction of the tire at a widthwise center region of the cap rubber portion, and is exposed to the tread surface to form a discharge path for allowing electrostatic charges of a vehicle body to be discharged to a road surface. An unvulcanized tread rubber for the tire is obtained by passing a high conductive unvulcanized rubber through a passage extending from an extruder unit to the back side of an extrusion orifice, to form at least part of the remaining potion of the tread rubber.

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: Candy mass including sugar and starch syrup is passed through a nozzle to which twisted-blades are mounted by a pair of a piston and a deposit cylinder for deposit, the candy mass being poured into a die. Consequently, candies having a beautiful marble pattern can be produced continuously.

Abstract: An extrusion diea plurality of die layers stacked one upon the other in a direction generally parallel to the central axis. Each of the layers has an annular flow distribution ring having an outer generally cylindrical surface and an annular feed ring surrounding and engaging the outer surface of the distribution ring. At the engaged surfaces of the feed and distribution ring, the flow from the feed ring is divided into a number of substantially equal flow portions. Seals between adjacent engaged surfaces confine the flow to between the circumferential surfaces of the feed and distribution ring. Half of the flow portions are directed to a recombination region on one side of the distribution ring, and half are directed to a recombination region on the other side of the ring. In recombining, weld lines are formed in high flow areas to minimize the delitarious effect of polimer degredation.

Abstract: A die for manufacturing honeycomb bodies includes batch supply holes which are opened to a backside surface of the die, slit channels which are communicated with the batch supply holes and are opened to a foreside surface of the die and a taper worked portion which is formed by working an outer peripheral portion of the foreside surface of the die in a taper manner. In the die mentioned above, at least one cut-out portion is formed to the taper worked portion of the outer peripheral portion.

Abstract: The invention relates to a multiple extrusion head for the production of profiles, in particular for tire production, with a fixedly arranged head flange, into which extruders open, and with a closed head having flow ducts, an adapter and a profile strip, which closed head is arranged so as to be capable of being braced against the head flange and of being pivoted away. The invention is defined in that the closed head has a receptacle which is open in the direction of the head flange and in which at least one open flow duct insert is removably arranged.

Abstract: Broad parts are formed on at least one passage including a passage for forming the thinnest layer among passages for respective resin layers of a multilayer sheet at an upstream side of a confluence. In the broad parts, clearances become larger to both ends of the passage along the width thereof.

Abstract: A decorative food formed of a plurality of kinds of fluid food materials and manufactured by using a mold is provided. The decorative food has an outside shape thereof conforming to an interior surface of the mold inclusive of an opening of said mold. The decorative food has a colored pattern divided into multiple divisions extending up to a central portion of the decorative food, in a direction to extrude the food materials into the mold, the colored pattern being formed such that the multiple divisions are arranged with substantially the same ratio at any of a cross sectional area intersecting the direction to extrude the food materials, and wherein the decorative food contains therein a foodstuff. Also disclosed are an apparatus and method for manufacturing the decorative food.

Abstract: An extrusion apparatus including at least one conical stator, and at least one conical rotor. The rotor is adapted for defibering or orienting a plastic material. The apparatus has an opening for receiving an elongate product or mandrel. The product or mandrel may be disposed in the apparatus such that, with the product or mandrel received in the opening, an extrusion conduit is defined in the opening between the product or mandrel and the rotor and stator. The rotor and stator are disposed with respect to one another to form a supply opening wherein the plastic material flows between the stator and rotor and is pressed into the extrusion conduit.

Abstract: Apparatus which provides a cylindrical chamber in which is contained a tool which is provided with a rotating movement for cutting up an extrudate delivered into the chamber into pieces and so that the pieces are distributed into a frozen composition mass delivered into the chamber and so that the mixture obtained is extruded through to a nozzle for passage of a composite mixture from the chamber.

Abstract: An extrusion die with a plurality of die layers stacked one upon the other in a direction generally parallel to the central axis. Each of the layers has an annular flow distribution ring having an outer generally cylindrical surface and an annular feed ring surrounding and engaging the outer surface of the distribution ring. At the engaged surfaces of the feed and distribution ring, the flow from the feed ring is divided into a number of substantially equal flow portions. Seals between adjacent engaged surfaces confine the flow to between the circumferential surfaces of the feed and distribution ring. Half of the flow portions are directed to a recombination region on one side of the distribution ring, and half are directed to a recombination region on the other side of the ring. In recombining, weld lines are formed in high flow areas to minimize the deleterious effect of polymer degredation.

Abstract: Apparatus and methods are disclosed where plastic extrudable food product is provided such as by a food cooker extruder and is mixed with a food color to form a complexly patterned food product, such as by a pattern forming die.

Abstract: An optical transmission line is formed and thereafter solidified using an optical transmission line forming material in the fluid condition. The optical transmission line formed between optical transmission terminals assures higher reliability and never generates disconnection or internal stress therein.

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 apparatus is disclosed for extruding gelled product by conveying a liquid mixture of chemically reacting components into and through a conveyance channel wherein the components chemically react to form a gel while being conveyed through the conveyance channel. The conveyance channel includes internal surfaces that form flow surfaces for conveyance of the product through the channel. The conveyance channel further includes a fluid flow path communicating with the internal surfaces so as to continuously apply a film of fluid over the internal surfaces as the liquid mixture is conveyed through the channel so that the liquid mixture is conveyed as a first phase within the channel surrounded by the film acting as a second phase to separate the first phase from the internal surfaces.

Abstract: A composite polymer fiber is produced employing at least two polymer compounds according to a process for producing a composite polymer fiber including the steps of supplying at least two polymer compounds; forming a belt flow by arranging alternately unmixed strips of the polymer compounds supplied; and injecting the belt flow after it is compressed such that the thickness of the belt flow may be longer than the width thereof and that multiple layers of the polymer compounds may be parallel to the longer axis of the fiber. According to this process, there is obtained a fiber having a multilayered structure, in which the thickness of each layer can be controlled with optical accuracy since the multilayered structure is formed in one step, and also having a rectangular cross section in which each layer in the fabric is oriented parallel to the longer axis of the fiber, so that the layers can be easily oriented, when woven into a fabric, in such a direction as to obtain high-intensity coherent beams of light.

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: 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: The invention relates to a device for joining together at least two material flows in a laminar coextrusion machine comprising at least two extruders, more precisely as many extruders as layers of different materials used, a device for joining together the flows coming from the extruders into a so-called global flow, said device being also called a distribution box, and an extrusion head supplied by the global flow. The joining device includes a main channel wherein open annexed channels called supply channels convey the different material flows coming from the extruders, the channels being provided with means for restricting the flow passage cross-section. The supply channel connecting each extruder to the main channel is at least partially in the form of a cylindrical plug valve having means which transform a cylindrical rod into a planar sheet.

Abstract: A device is disclosed for producing a continuous formed confection of frozen dairy product and flavoring gel combined in co-extensive strips. The device includes an extrusion die provided with a shaping bore for extrusion-forming the frozen dairy product and a channel downstream of the shaping bore for laying a continuous bed of flavoring gel on the frozen dairy product. The channel includes a plurality of discharge orifices for depositing stripes of flavoring fluid on the frozen dairy product.

Abstract: An elastomeric extruding apparatus having a head, to which a plurality of extruders are coupled, and a rotatable, driven roller disposed at the front end of the head so as to form an extruding space between the roller and the head. The head is provided with a passage arrangement, through which the elastomeric materials pass, eventually opening into the extruding space. The extruding space has a uniform chamber extending from the opening of the passage arrangement and a finishing chamber communicating with the uniform chamber for shaping the elastomer into its final sectional shape.

Abstract: A single head forms an outside layer material supply passage connected through to an annular slit at joined portion, a reinforcing material supply passage and an inside layer material supply passage. An outside rubber layer is supplied to the outside material supply passage. A reinforcing cloth is supplied to the reinforcing material supply passage, and an inside rubber is supplied to the inside layer material supply passage respectively. A vacuum is formed up to the pressure of the joined portion by reducing under a vacuum the inside of the reinforcing cloth supply passage, thereby removing water or gas such as air attaching to both surfaces of the reinforcing cloth and increasing the adhesion of the outside rubber layer and the inside rubber layer with the reinforcing cloth being half there between.

Abstract: An electronic device in a cavity in a mold is encapsulated by a composite plastic having two materials placed, respectively, in sequential locations in a reservoir in the mold. The first material has desirable properties when in contact with the surface of the device, e.g., better adhesion. The second and different material has other desirable properties, e.g., mechanical strength, low moisture permeability, etc. The first location is first in line in a direction through the mold chambers to the cavity. The two-part encapsulant is injected into the cavity without significant turbulence so as to avoid much mixing of the two materials. This creates a boundary layer of the first material which preferentially applies a coating to the device while the second material substantially fills the bulk of the space in the mold cavity. A composite encapsulation is formed having overall superior properties.

Abstract: An extrusion die for the extrusion of continuous hollow sections of plastic materials reinforced with fibers or molecules. Both the outer nozzle and inner mandrel are rotatable and have radial channels within them to allow the extrudate to flow through either the body of the nozzle or through the body of the mandrel in a direction perpendicular to the axis of the extrusion die into the space between them to impart a radial component to the fibers. Likewise, a helical channel formed either inside the nozzle or the mandrel or on a surface of either imparts a tangential component to the fibers. When formed inside the nozzle or mandrel, the helical channel forms a hollow enclosed passageway open at opposite ends through which the extrudate flows. The flow may also be straight through the die which gives the fibers an axial component.

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 extrusion die for forming a honeycomb structure such as a catalyst carrier of a catalytic converter for internal combustion engines is provided. The extrusion die includes material inlet ports and latticed slits. The slits are formed in a die base and have first inner walls leading to an outer surface of the die base and second inner walls leading to the material inlet ports, respectively. Metal-plated layers are formed on the first inner walls of the slits to define outlets of the die and have the width smaller than those of the second inner walls of the slits, respectively. This die structure facilities easy extrusion of the honeycomb structure made up by thin honeycomb walls with a smaller extrusion resistance.

Abstract: An apparatus that comprises a body including a reservoir adapted for receiving a quantity of fluid and a plurality of fluid distribution channels each having a length and a cross-sectional area and being in fluid communication with and extending from the reservoir from a first end and terminating at a second, distal end in an orifice. The apparatus further comprises a distribution chamber in the body for commonly receiving the fluid exiting each of the orifices, for merging the fluid exiting each of the orifices into at least one continuous coating stream, and for equalizing the pressure of the fluid, the distribution chamber having a first side in fluid communication with the plurality of fluid distribution channels and a second side that is open to allow the fluid to exit the body for uniform distribution onto the web.

Abstract: An apparatus supplies food paste material sheets at a predetermined interval on a surface moving at a predetermined speed. The apparatus includes a horizontally arranged first roller adapted to be rotated to receive a continuous food paste material sheet on the circumferential surface thereof; means for severing the continuous sheet on the circumferential surface at a predetermined interval in the circumferential direction into a plurality of sheet segments or the above-stated sheets; a first peeler means provided at a predetermined position on the lower half portion of the circumferential surface of the first roller for peeling off the severed sheet segments from the circumferential surface which segments have been successively brought to the above-noted predetermined position; and a second horizontally arranged roller provided under the first roller. The second roller is adapted to be rotated to sequentially receive the sheet segments from the first roller.

Abstract: Process and device for producing two-colored or multicolored switchboard films, dashboard films or dashboards for motor vehicles produced therefrom using at least one backing film or backing layer, at least one upper film or upper layer which is arranged thereon and contains dyes and/or color pigments. The polymer melts for these films or layers come from two or more extruders and are supplied first to an adapter or a black box having at least one opening or a gap for the backing film or layer and at least one further opening for the upper film or upper layer. According to the invention, an adapter or a black box is used in which a wedge-shaped projection or a projection of triangular cross section is arranged. At least two different-colored polymer compositions in melt form, having identical viscosity or virtually identical viscosity (difference in MFI at 230.degree. C./2.16 kg of 0 to 0.

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: 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.