Abstract: The present invention relates to a method for making a silicon balloon catheter in which a first tube having its outer diameter slightly smaller than that of a desired catheter is formed by an extruding method, mold lubricant is coated at a portion of a balloon injection opening, a thin film type second tube is formed at the coated outer surface of the first tube by a second extruding, and then the catheter is vulcanized and cut. As a result, when liquid is injected to an expansion tube, the second tube is separated from the first tube, thereby performing a function as a balloon.

Abstract: The present invention is directed to a method for manufacturing a curved hose. The method is comprised of the steps of forming a hose pre-assembly, partially curing the hose on a linear mandrel, and then completing the curing of the hose pre-assembly on a curved mandrel.

Abstract: A plastic pipe has a multiple layer wall construction including major and minor wall portions. The major wall portions are formed with first corrugations and are separated from one another by the minor wall portions which are formed with second corrugations and a bowed wall part which is of the same diameter as the first corrugations. The second corrugations are smaller in diameter than both the first corrugations and the bowed wall pipe. The wall construction is cut at the bowed wall part to produce two pipe sections which couple with one another. One of those pipe sections has an open ended bell converted from the bowed wall pipe and the other pipe section has a male spigot formed by the second corrugations of the wall construction.

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

Abstract: A process is disclosed producing an intermediate transfer member used in an image-forming apparatus in which an image formed on a first image-bearing member is transferred to a second image-bearing member. The process has the steps of melt-extruding an extrusion material from a circular die by means of an extruder and thereafter making the same into a desired shape to obtain a cylindrical extruded product, and forming the resultant cylindrical extruded product into the intermediate transfer member. The cylindrical extruded product contains a thermoplastic resin and an ion-conductive resistance control agent, and a ratio of the diameter of the intermediate transfer member obtained to the die diameter of the circular die is from 0.5 to 4.0. Also disclosed are an intermediate transfer member obtained by the production process, and an intermediate transfer member having the intermediate transfer member.

Abstract: A method for manufacturing a fuel transporting hose which is low in manufacturing costs and is superior in characteristics, including insertability, sealability and pull-out resistance. The method includes the steps of extrusion-molding an unvulcanized hose having fluoro rubber as an inner layer without using a mandrel, vulcanizing the unvulcanized hose so as to form a fuel transporting hose having a fluoro rubber inner layer, and forming a fluorine-modified silicone lubricating layer on the inner peripheral surface of the fluoro rubber inner layer.

Abstract: A process for producing an endless belt includes melt-extruding an extrusion material into a cylinder by means of an extruder, where the extrusion material has a tensile break strength of 400 kgf/cm2 or above and a breaking extension of from 3.0% to 250%, and where the extrusion material is extruded in an extrusion ratio of from 1.05 to 2.80 while a gas is blown into the inside of the melt-extruded cylindrical product.

Abstract: A continuous process and apparatus for producing oriented plastic tube comprising the steps of extrusion, temperature conditioning, diametrical expansion and cooling, characterized by the step of inducing axial draw of the tube between first and second haul-off means located upstream of the expansion step.

Abstract: A pipe section formed of a polymeric material which has a substantially constant thickness throughout, the terminal edge of the female connection having a reinforcement structure which rigidifies the end of the female connection and prevents deformation, the pipe section preferably having a flared end, and the reinforcement structure preferably being a semicircular channel formed at the end of the pipe section by a mandrel after initial extrusion of the pipe section; along with a method and apparatus for forming the pipe section, a pipe assembly including such pipe section, and a method of forming the pipe assembly.

Abstract: This invention concerns a method of manufacturing a highly conductive polytetrafluoroethylene sheet; a method of manufacturing a highly conductive unsintered polytetrafluoroethylene sheet: and a method of manufacturing a highly conductive sintered sheet. In the first method, a paste of polytetrafluoroethylene powder admixed with conductive substance and extrusion lubricant is extruded to preform an unsintered tube-like material, and at least one place on the circumference of this extruded material, the material is cut open longitudinally and the resulting sheet is calendered if necessary. The second method includes a sintering process for the sheet. This invention also concerns a highly conductive polytetrafluoroethylene sheet having a wide-width and long-length, which is obtained by the above-mentioned method. This sheet is not less than 170 mm in width and has variance of volume resistivity (conductivity) in the longitudinal direction, 10% or less, preferably 7% or less in the cross direction.

Abstract: A method for extruding, calibrating, and cooling a multi-layer profile comprising polyethylene terephthalate (PET) and a barrier material, and the product produced by such method. The method further encompasses the use of a standard can seamer and standard can closures to seal said extruded profile with food contained therein. The invention permits the extrusion and effective cooling and calibration of larger diameter and smaller thickness PET profiles or pipes in commercial quantities with effective control of quality and eccentricity of the profiles produced.

Abstract: An elongated tubular structure of plastic strands is bisected along its axis to form open-topped self-supporting half-shells that can be used in cooling towers. The half-shells are stackable and can be transported in densely packed bundles.

Abstract: The process according to the invention for producing large-bore thick-walled pipes made of polyethylene comprises extruding the polymer composition out of an annular die 3 and subsequently cooling the melt 7 emerging from the die 3 using water as the coolant from the outside, the melt 7 emerging from the die being additionally also cooled with water from the inside. In order to ensure the internal cooling, according to the invention floating plugs 11 and 12 are inserted, which plugs are fixed in their physical position relative to the extrusion die 3 by means of retaining elements.

Abstract: A non-allergenic resistive exercise device is described. The device is in the form of a relatively thin elongate band of thermoplastic elastomer. In one embodiment of the invention, the device is in the form of a seamless endless band, while in another, the band is substantially strip-shaped. The bands can be textured to enhance the ability of a user to grip them during use, and the bands can also be printed or otherwise ornamented. The exercise devices of the instant invention are latex-free so as to be non-allergenic, do not require supplemental powdering of their surfaces, and are virtually odor-free. Several methods for producing the bands are also described. In one method, the thermoplastic elastomer material is extruded through an elongate-shaped die to form a cast film, which is solidified and cut to the desired length for use. In this method, the die in desirably substantially dog bone-shaped, in order to produce elongate bands having thickened side edges.

Abstract: A process and an extrusion arrangement are suggested for cutting extruded hollow profiles while heated from the extruding process heat into the required lengths by means of a high-energy beam or jet moved along with the extruding operation. The interior of the extruded hollow profile is filled with a light-weight material at least at the cutting points. The light-weight material is advantageously an expansive foam mass, such as an aluminum foam or a plastic foam. The filling of the extruded hollow profile takes place either by coextrusion or by way of an arbor or a hollow-chamber bottom die of the extrusion arrangement.

Abstract: A method of manufacturing ceramic filter media for water filters involves the steps of mixing a plurality of raw ceramic materials and a plurality of extrusion-aid materials to form a mixture of constituent materials, extruding the constituent materials to form tubular filter media, drying the tubular filter media, and firing the tubular filter media to create ceramic tubular filter media. The step of drying the tubular filter media preferably comprises placing the tubular filter media on top of rotating rollers which dries the tubular filter media evenly and preserves the desired characteristics of the tubular filter media.

Abstract: Conventionally produced edible tubular casing is improved in its mechanical properties by being exposed to ultraviolet spectra in the range of 180 nm to 420 nm. The so treated casing is humidified, collapsed and wound onto a reel. The reel of tubular casing may be transported to a point of use where it is unwound, inflated, shipped and cut into lengths as desired.

Abstract: Hoses are often reinforced with fabric to improve their performance characteristics, such as burst strength. For instance, radiator hose used in automotive applications is generally reinforced with continuous yarn. However, it is a labor-intensive process to manufacture such hoses which include fiber reinforcements. A substantial amount of material waste also generally occurs in the manufacture of such fiber-reinforced hose. By utilizing the technique of this invention, hose which has a high level of burst strength can be manufactured without including continuous yarn reinforcement.

Abstract: Method for manufacturing aspirator tubes (10) for medical and dental use which are provided with two opposite air apertures (13) adjacent at least one end thereof. The air apertures are made in a tube length which is moving axially and is cut to individual aspirators tubes. The apertures are made and the tube length is cut by means of continuously rotating cutters (17, 18, 22, 23) which are cuttingly engaged with the tube length at predetermined revolutions only while said cutters are brought to idle therebetween, withdrawn from the tube length.

Abstract: An umbrella fabrication method including the steps of (I) preparing a bamboo tube by cutting off nodes from a bamboo cane, (II) bonding a resin compound to the inside of the bamboo tube thus obtained, so as to obtain a resin bonded bamboo tube, and, (III) cutting the resin bonded bamboo tube into finished pieces, each finished piece having a flat bamboo base, and a resin rib body bonded to one side of the flat bamboo base.

Abstract: A method for producing a weather strip having a molded end portion joined to an end of an extruded weather strip having a base portion and a tubular seal portion. The method includes the steps of cutting-off a portion of the tubular seal portion from the end of the extruded weather strip with the base portion thereof remaining uncut, placing the uncut base portion of the end of the extruded weather strip in a cavity of a mold, placing a core along the uncut base portion, injecting a molding material into the cavity to mold a tubular part having a configuration conforming to the cut off tubular seal portion integrally with a fin-like end part extending from the tubular part, opening the mold, and removing the core from the tubular part along a reverse face of the fin-like end part.

Abstract: A process for fabricating an article having a rigid foam core and a resilient outer plastic shell by extruding heated thermoplastic material to form the shell, partially hardening the extruded a plastic shell, injecting a liquid foam material into the interior of the partially hardened plastic shell, and cooling the shell and the liquid foam material to fully harden the plastic shell and the foam under conditions which cause the article to have a predetermined shape and size.

Abstract: A hollow polysulfonic fiber intended for a selectively transmissive membrane contains a hydrophilic polymer which is cross-linked into a water-insoluble form (for example polyvinylpyrrolidone) and is used in the form of a hydrogel containing water. A method for the production of a membrane module consists in spinning a hollow fiber by the use of a spinning solution containing a polysulfonic resin and a hydrophilic polymer, wetting the fiber above the saturated moisture content, and then, with the wet condition maintained, subjecting the fiber to the processes of module molding and radiation induced cross-linking, these processes being performed in either order. The method provides a selectively transmissive hollow polysulfone fiber membrane which displays less elution into water and a sharp molecular weight fractionation, so as to be usable safely in the fields of medicine and foodstuffs.

Abstract: A method of manufacture is disclosed for a PTCA guiding catheter. The catheter includes a lamination of an inner structural polymer tube, a lubricating means disposed on the inside of the inner structural polymer tube, a reinforcement means embedded at least partially within the inner structural polymer tube, and an outer structural polymer tube embedded at least partially within the reinforcement means and fused at least partially to the inner structural polymer tube.

Abstract: A method for making differential stiffness tubing for medical products, such as catheters. The method produces a tubing that has a stiff section and a flexible section joined by a relatively short transition section in which the materials of the stiff and flexible sections are wedged into each other in a smooth gradual manner to produce an inseparable bond between the materials without abrupt joints. The method also employs a resin modulating system that minimizes the length of the transition section by minimizing the volumes in all flow channels of the co-extrusion head used to produce the tubing.

Abstract: Process for forming a dimensionally variable tubular member for use in catheterization procedures. The process includes a mechanism for extruding a tubular member. A variable speed puller pulls the tubular member through or from the extrusion means at a selectively variable speed. A variable air or gas pressure supply supplies pressurized air or gas to the extrusion mechanism at a selectively variable rate. The dimensionally varying tubular member may be cut to desired lengths for use as catheter shafts or catheter soft tips. The process may include forming a tubular member having a dimensionally varying first layer and a dimensionally varying second layer, wherein a portion of the first layer at a distal end of the tubular member is removed.

Abstract: Blanks serving for the production of insulating material and folding packs have to be provided with folding and bending lines. These folding and bending lines in the plastic foam must not break when the blank is folded. This is achieved according to the invention by embossing the folding and bending lines for forming the blank into the "fresh" web of material which for the most part still contains expanding agent. The folding and bending lines formed in this way have surprisingly proved to form durable hinge lines in the plastic foam material and make it possible to fold up the blank for forming a folding carton without it breaking or cracking.

Abstract: Hydraulically settable mixtures and methods for extruding such mixtures into a variety of objects which are form-stable in the green state. High green strength is achieved by increasing the yield stress of the mixture while maintaining adequate extrudability. Optimizing the particle packing density while including a deficiency of water yields a hydraulically settable mixture which will flow under pressures typically associated with the extrusion of clay or plastic. In addition, a rheology-modifying agent can be added to increase the yield stress of the mixture while not significantly increasing the viscosity. The desired strength properties and other performance criteria of the final hardened extruded product are controlled by adding aggregates, fibers, a hydraulically settable binder, water, and other admixtures.

Abstract: Methods and apparatus for continuously extruding a hydraulically settable mixture and simultaneously placing continuous filaments within the extruding mixture to yield articles having a filament-reinforced, hydraulically settable matrix. The filaments can be placed within the mixtures in a parallel configuration, a helical configuration, or combinations thereof, in order to yield an article having the desired properties of, e.g., tensile strength, flexural strength, hoop strength, burst strength, toughness, and elongation ability. The desired properties of the hydraulically settable mixture, as well as of the cured hydraulically settable matrix of the hardened article, may also be adjusted by including varying amounts and types of aggregates, discontinuous fibers, binders, rheology-modifying agents, dispersants, or other admixtures within the hydraulically settable mixture.

Abstract: A method for forming an article from recyclable plastic materials includes progressively heating thermoplastic solid particles simultaneously with mixing, melting and conveying the particles, prior to delivery of molten material to an extruder. The process is particularly suitable for the continuous extrusion of elongated members having a plurality of internal wall surfaces defining elongated cavities within the member. The apparatus embodying the present invention includes a heated mixer-conveyor that simultaneously heats, melts, mixes and conveys thermoplastic material from an inlet port at which the material is received in solid particulate form, to a discharge port at which the material is in a substantially liquid state. A die particularly adapted for the continuous extrusion of an elongated member having internal walls shaped by surfaces within the die cavity is also disclosed.

Abstract: In a method of forming a hollow product in a molding apparatus having an upstream and a downsteam end a parison of thermoplastic material is extruded in a molten state from a heated extruder at the upstream end and moved through a product shaping region towards the downstream end of the apparatus. The material is cooled by passing a cooling medium internally of the product from the downstream end towards the upstream end of the apparatus.

Abstract: Method of manufacturing a dental aspirator by extruding a continuous tube with a bellows portion. The tube is angled to form a number of folds, each of which consists of two cup-shaped portions having concave surfaces facing each other. One cup-shaped portion is made smaller than the other, allowing them to be snapped together. The bellows are formed from the tube wall by chilled mold chains. At the same time, the tube is profiled to form an end portion at the suction end of the finished aspirator.

Abstract: A seamless tube useful in making a roofing batten is extruded from a polymeric material consisting essentially of a major amount of poly(ethylene terephthalate) and a minor amount of at least one polyolefin, flattened in a vacuum sizer so as to define two plies, and milled and drawn so as to orient the tube longitudinally. As milled and drawn, the tube is oriented so as to have a tensile strength of at least about 25,000 psi in a longitudinal direction. The plies are punched so as to have holes therethrough at spaced intervals along the tube. When used to make a roofing batten to coact with conventional fasteners, such as roofing screws, the tube exhibits superior characteristics of split resistance and pull-through resistance.

Abstract: Polyester prepolymer granules with open-ended cavities provide greatly improved solid state polymerization rates by improving reaction by-product diffusion characteristics.

Abstract: A method for manufacturing concrete panels by continuously pressing and an apparatus for carrying out the method. The concrete panels are successively manufactured by continuously feeding pallets onto a conveyor, feeding a concrete material onto the pallets, continuously pressure frames against the concrete material from the upper side and both lateral sides of the concrete material while imparting vibrations to the pressure frames, forming hollows in the concrete material by thrusting a rotary screw-type core rod therethrough to provide a panel shape hollow molding, and cutting the molded concrete material into a length corresponding to the length of each pallet. In the manufacture process, an organic or inorganic fiber material may be incorporated into the concrete material for the purpose of reinforcement of the finished products.

Abstract: A seamless tube useful in making a roofing batten is extruded from a polymeric material consisting essentially of a major amount of poly(ethylene terephthalate) and a minor amount of at least one polyolefin, flattened in a vacuum sizer so as to define two plies, and milled and drawn so as to orient the tube longitudinally. As milled and drawn, the tube is oriented so as to have a tensile strength of at least about 25,000 psi in a longitudinal direction. The plies are punched so as to have holes therethrough at spaced intervals along the tube. When used to make a roofing batten to coact with conventional fasteners, such as roofing screws, the tube exhibits superior characteristics of split resistance and pull-through resistance.

Abstract: A method of producing a spliceless annular tread cap (2), whereby a portion (23) of an extruded tube (21) of green elastomeric material is fed inside an annular body (8), the inner annular surface (17) of which presents a diameter approximately equal to but no smaller than the outside diameter of the tubular portion (23), and negatively reproduces the pattern of the finished tread cap (2). The tubular portion (23) is expanded and calendered against the inner surface (17) of the annular body (8) by means of a roller (34) moved into a position coplanar with and eccentric in relation to the annular body (8).

Abstract: A thermoplastic tube, and method for forming such a tube, has a tube body portion formed from an inner layer of thermoplastic material, a barrier layer, and an outer layer of thermoplastic material. The outer layer does not extend completely about the periphery of the tube body and a strip of thermoplastic material having the same composition as the inner layer, fills each gap in the outer layer to form a smooth surface about the tube. The strip may be transparent or of a color different than the color of the outer layer. In a preferred tube, a first layer of adhesive material is provided between the inner layer and the barrier layer, and a second layer of adhesive material is provided between the barrier layer and the outer layer and strip.

Abstract: An apparatus for manufacturing a hollow synthetic resin product, including a movable parison guide and a movable lower molding portion which align an extruding head, the parison guide and an end of the lower molding portion in a perpendicular plane. The lower molding portion is moved in a direction perpendicular to the perpendicular plane while a parison is extruded from the extruding head, while the parison guide is moved in a direction crossing the moving direction of the lower molding portion in accordance with a shape of a groove of the lower molding portion to accommodate a first portion of the parison in the groove. A cutter cuts the parison in a predetermined length when the predetermined length thereof is extruded, while a parison pinch holds a portion of the parison to be cut immediately before the parison is cut.

Abstract: Hoses are often reinforced with fabric to improve their performance characteristics, such as burst strength. By utilizing the technique of this invention, hose which has a high level of burst strength can be manufactured without including continuous yarn reinforcement. This invention specifically reveals a process for manufacturing a hose which involves the steps of (1) extruding a rubber composition into the form of a tube, wherein the rubber composition contains (a) an EPDM alloy comprised of (i) standard EPDM rubber, (ii) an EPDM rubber having thermoplastic side chains grafted thereto, and (iii) dispersed thermoplastic wherein the thermoplastic is selected from the group consisting of nylons, polyesters, and polyphenylene oxides, (b) an EPDM rubber, (c) carbon black, (d) at least one curative, (e) zinc oxide, (f) a processing oil, and (g) stearic acid; (2) shaping the tube into the geometric form desired for the hose; and (3) curing the rubber composition at a temperature within the range of 130.degree. C.

Abstract: A method for producing a seamless tube for use as an intermediate image-transfer belt, comprising the step of continuously extruding an electrically conductive composition comprising the following components (a), (b) and (c) to form an unstretched seamless tube having a thickness of 50 to 1000 .mu.m and a sheet resistance of 10.sup.5 to 10.sup.13 .OMEGA./.quadrature.: (a) a thermoplastic aromatic polycarbonate resin, (b) a thermoplastic poly(alkylene terephthalate) resin and (c) acetylene black, the amount of the component (a) being from 60 to 95 wt. % of the total weight of the component (a) and the component (b) the amount of the component (b) being from 40 to 5 wt. % of the total weight of the component (a) and the component (b), and the amount of the component (c) being from 10 to 25 parts by weight for 100 parts by weight of the total amount of the component (a) and the component (b).

Abstract: The method and apparatus for producing members (4) of extrudable material, for example a ceramic or synthetic plastic material, use a nozzle (2) composed of a plurality of segments (21 to 25) abutting without gaps and having extrusion ducts (28), segments (21, 22) of the nozzle being moved relative to one another, for example transversely relative to the direction of extrusion. With this method and apparatus it is possible to produce in a single operation members of which the structures, such as open ducts (40), change their relative positions and cross one another.

Abstract: Ceramic tubes are manufactured from a mixture that includes ceramic powder. The mixture is extruded through a die to form a tube. The tube is passed through an open-ended dryer, calciner, transition zone, sintering furnace, and cooler. Thereafter, the tube is cut to the desired length (which may be very long). The quality of the tube is enhanced by applying a vacuum to the mixture prior to extrusion. For tubes made of non-oxide ceramics, an inert atmosphere is maintained both inside and outside the tube in all sections of the equipment that operate above 200.degree. C. A controlled tension is applied to the tube by means of first pinch rolls disposed downstream of the dryer and second pinch rolls disposed downstream of the cooler.

Abstract: A continuous, non-hesitant apparatus and process for producing a molded body of plastics material and for simultaneously securing the molded body to a tubular body by means of a plurality of heading units mounted in series on a continuous conveyor, each heading unit having a mold cavity associated with the mold arm slidably positionable with respect to a mandrel arm having a mandrel, press rod and mold core secured thereto, the mold core and press rod in coaxial alignment with the mold cavity, each of which responsive to a camming surface, the tubular body positioned on the mandrel and brought in registration with a continuous web of hot plastics material which is positioned at one end of the tubular body, the tubular body and mold core then positioned within the mold cavity responsive to the camming surfaces for a time sufficient to form the molded body and secure the molded body to the tubular body, the molded body and tubular body then released from the heading unit, the heading unit recirculating to obtai

Abstract: A parison thickness control system includes an extruder die and a mandrel which are movable relative to each other to change wall thickness of a parison extruded between the extruder die and the mandrel during an extrusion or forming cycle of the parison. A parison control pattern is derived by manually inputting master points each defined in terms of a target parison wall thickness and an elapsed time during the parison extrusion cycle. A further parison control pattern is derived by performing the spline interpolation to interpolate between the master points. A still further parison control pattern is derived by correcting the above-noted further parison control pattern to allow the maximum or minimum value of the master points to indicate a limit value for the target parison wall thickness during the parison extrusion cycle. The parison extrusion cycle is divided into a given number of equal time intervals to define cycle points.

Abstract: A hollow fiber of amorphous, hydroxy-ethylated poly-(2,6-dimethyl-p-oxyphenylene) (PPO-OH) with a glass transition temperature (Tg) of from 180.degree. to 200.degree. C. is disclosed, which is formed by a high-density, microporous layer on a macroporous backing, and having an outer diameter comprised within the range of from 450 to 550 .mu.m and an inner diameter comprised within the range of from 250 to 400 .mu.m.The process for preparing the hollow fibre and the use of said fibre in the processes of separation of gas mixtures are disclosed as well.

Abstract: A condom having a blow formed tubular main sheath portion, and a method for making the condom. Blow extrusion techniques of fabrication are described, together with the use of various thermoplastic materials of construction, including polyurethanes, polyether block amides, styrene-rubber-styrene block copolymers, ethylene-octene copolymers, and polyesters. The condom is made by blow extruding a tubular film of thermoplastic material to form a main sheath portion, severing the main sheath portion into one or more condom pieces, and sealing one end of each piece.

Abstract: A method of making a balloon catheter. The method includes the steps of providing a tube having an outer surface and a plurality of lumens including first and second lumens, the tube including a first lumen access opening in the outer surface communicating with the first lumen; simultaneously coating a first portion of the outer surface with an amount of a bond preventing agent effective to prevent bonding to the first portion of the outer surface and plugging the first lumen access opening; and subsequently coating a second portion of the outer surface and the coating of bond preventing agent on the first portion of the outer surface with a polymeric bonding composition, wherein a resilient overcoat layer is created which is fixed to and integral with the tube proximate the second portion of the outer surface and free from adherence to the tube proximate the first portion of the outer surface. An alternate embodiment provides a method of mass-producing balloon catheters.

Abstract: The process for production of polyacrylonitrile hollow threads with a stable, asymmetric pore structure by a dry-wet-spinning process with glycerine-based core liquids, definite draw and after treatment conditions and a treatment with alcohols and drying.

Abstract: A manifolded, multiple-pin die apparatus and method processes potentially explosive material to form longitudinally perforated cylindrical pellets for use as gun propellants. A main entrance passage formed in mating manifold blocks gradually changes in cross-sectional configuration from circular to figure-eight, and then branches in a gently curved manner. The divergent branches formed then further branch in the same manner and feed circular cross-section passages leading to extruding dies wherein a series of die pins extend axially through a discharge passage. Each die comprises a central core member supporting an outer shell via radial ribs which are configured to form flow passages of hour-glass configuration. No change of flow direction in the entire apparatus exceeds fifteen degrees.