Abstract: An annular co-extrusion die for extruding multi-layer tubular plastic film has inner die members stacked one upon another. The inner die members have radially outwardly extending surfaces forming radially outwardly extending helical passages between respective pairs of 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. Each inner die member forms with an adjacent die member a first feed passage extending at least partly around the inner die member radially inwardly of the helical passages, the inner die member and the adjacent die member having a circumferentially extending clearance therebetween to enable plastic material fed into the first feed passage to pass through the clearance into the helical passages.

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 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 channels within them to allow the extrudate to flow through either the body of the nozzle or of the mandrel into the space between them to impart a radial component to the fibers. Likewise, a helical channel formed in either the nozzle or mandrel imparts a tangential component to the fibers. The flow may also be straight through the die which gives the fibers an axial component.

Abstract: A method and an apparatus for processing food into a tubular shape is provided in which a die for processing the food includes a guide plate having a material outlet and a cylindrical feed pin having a water outlet at its center co-axially housed in the material outlet. The guide plate and feed pin cooperatively define a ring-like opening. Food material is extruded out of the ring-like opening in a tubular shape. Simultaneously, hot water is expelled out of the water outlet of the feed pin, flows into and fills a hollow inside the tubular food material. The hot water in the hollow prevents the wall of the tubular food material from collapsing and also accelerates coagulation of the food material. Food material is thus continuously processed into a tubular shape. An extruding die for performing the described method is also provided.

Abstract: A in-line extrusion die is disclosed including a cylindrical mandrel and a die bushing surrounding the mandrel and forming therebetween a passageway leading to an extrusion orifice. The mandrel is mounted to one side of a spider plate and a tailcone is attached to the other side thereof. A die body containing a melt chamber surrounds the tailcone and forms a conical passageway therebetween. A thermocouple is mounted at the apex end of the tailcone for measuring the temperature of the melt as the melt flows from the melt chamber and through the conical passageway. The spider plate contains a plurality of openings which communicate with both passageways and allow the melt to pass through the plate and thence to the extrusion orifice.

Abstract: An extrusion head for extruding a polymer into a parison for blow molding and including a die ring and a mandrel. The die ring and mandrel each include a frustoconical portion. One frustoconical portion is shaped over its full length to define an ovalized annular outlet. The frustoconical portion is also shaped over less than its full length with a recess that is rotationally offset from the first and generally located upstream therefrom. The shapings result in the prison being extruded in a controlled manner through the outlet orifice with a predetermined area of increased thickness.

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: Underground pipelines that carry wastewater, water, natural gas, and industrial fluids deteriorate with age. This invention is a process and apparatus for installing a thermoplastic liner in a dry pipeline to accomplish in situ rehabilitation. It involves extruding a tube of thermoplastic liner material within the interior of a dried and preheated pipeline in situ, said tube having an outside diameter smaller than the inside diameter of said pipeline. The tube is next expanded so that the outside diameter of said tube is substantially equal to the inside diameter of said pipeline. The expanded tube is then cooled and hardened in a liner configuration.

Abstract: The relationship between the average degree of roughness of the faces of rough appearance, expressed in microns, and the percentage by weight of units derived from vinyl acetate in the copolymer of which the film consists is greater than 0.019.The film is extruded in the form of an extruded sleeve which is cooled in the die by a circulation of a coolant fluid whose temperature T satisfies the relationship: ##EQU1## in which Tc is the temperature at which the Napierian logarithm of the relationship between the length at break and the initial length of a test specimen of the copolymer has a value of 87% of its value at 180.degree.Tm is the mean temperature of the copolymer as it leaves the diea is equal to 0.24G is given by the relationship .rho..times.Cp.times.V.times.H.sup.2 /.lambda..times.Lin which.rho. is the density of the copolymerCp is the specific heat of the copolymerV is the mean flow velocity of the copolymer through the extrusion dieH is the height of the gap between the core and the extrusion die.

Abstract: An apparatus to manufacture a cellulose food casing including a nonderivatized cellulose film precipitated in tubular form from an extruded thermoplastic solution of cellulose and an amine oxide cellulose solvent.

Abstract: An improved manifold calibration finger which can be used in conjunction with a die head in the extrusion of a plastic with the manifold calibration finger comprising a first section comprising an elongate tubular member having a grooved outer surface and an elongate central channel extending through the first section from one end of the first section to the other.

Abstract: A multi-hole tube extrusion die comprises a female mold die having a flat opening and a mandrel having comb-teeth-like molding portions arranged in the opening. A heated material is extruded between the female mold die opening and the comb-teeth-like molding portions of the mandrel to form a tube having a multi-plicity of holes. An interval between each of the comb-teeth-like molding portions at the opposite ends of the mandrel and the comb-teeth-like molding portion adjacent to the outermost comb-teeth-like molding portion is set to be smaller than an intervals between the female mold die opening and each of the outermost comb-teeth-like molding portions and to be larger than an interval between adjacent ones of the other comb-teeth-like molding portions. Additionally, the outermost comb-teeth-like molding portions are larger in width than the other comb-teeth-like molding portions.

Abstract: A method of manufacturing an etched extrusion, the method comprising the steps of extruding a thermoplastic material to produce a hot extrusion, and contacting the extrusion, while the extrusion is still hot, with a mixture of at least two fluids having different thermal conductivities so that the extrusion develops an uneven outer surface due to different rates of shrinkage caused by the different thermal conductivities.

Abstract: A method and machine for making churros. The machine extrudes churros through a die. The die has a central mandrel so that hollow churros are made which can be filled. The churros are extruded from the machine when an operator rams a crank on the machine. Consistent, high quality churros can be made at high production rates suitable for use in a restaurant.

Abstract: Extrusion die apparatus and an extrusion method for extruding large-cross-section honeycomb structures from plasticized ceramic batch materials are described, the apparatus comprising a die having a support rod connected to its central portion, the support rod being anchored to support means upstream of the die. The support rod and support means act to limit die distortion during extrusion, reducing die strain and stress to levels permitting large honeycomb extrusion without die failure. Dies of optimal thickness are disclosed which reduce the maximum stresses exerted on the die during extrusion.

Abstract: A screw for a double-shaft extruding device having a shaft and a spiral flight provided at an outer periphery of the shaft. A height of the flight from an axis of the shaft is substantially constant. An angle of torsion of a spiral of the flight becomes smaller toward a shaft distal end. A cross-sectional area of extrusion formed by the shaft and the flight continuously increases from the shaft distal end to a shaft proximal end. Material can be smoothly discharged and completely extruded.

Abstract: Tube multi-pack methods of manufacture are disclosed. The tube multi-packs that are produced by the method of the present invention are one-piece tube multi-pack including an elongated thin-walled tubular element made of transparent flexible plastic material with inner and outer peripherally extending walls. At least one thin-walled web section is integrally connected to the inner peripheral extending wall of the tubular element and has greater flexibility than the tubular element in order to adjustably accommodate a plurality of separate discrete products positioned on opposite sides of the at least one integral web section. The at least one integral thin-walled web section may be connected to the inner peripherally extending wall of the tubular element at different relative locations, for example, in a spiral or curvilinear or other shaped path throughout the tubular element.

Abstract: Apparatus for producing a tubular plastic product, for example film, has a die body with inner and outer die members defining between them an annular space, and a first inlet for feeding a first stream of resin into the annular space. The inner and outer die members define an annular chamber communicating between the first inlet and the annular space. The resin stream from the first resin inlet divides into two substreams which flow in the annular chamber in opposite directions about the longitudinal axis of the annular space and then join. A second inlet downstream of the first inlet feeds a second stream of resin into the annular space and over the weld line of the annular resin stream. The annular resin stream is expressed through an annular orifice to form the tubular film.

Abstract: The invention is to improve a molding nozzle assembly for producing hollow cylindrical snack foods. In order to produce hollow cylindrical snack food products of even thickness and the hollow spaces being almost perfectly circular, it includes a nozzle body having a throat, a conical hole converging to the throat and a cylindrical hole extending from the throat. An elongated pin is set in the nozzle passing through the conical hole, throat and cylindrical hole, and a mount is fixed to the nozzle body. The pin has a conical head at one end thereof and a disk collar fixed to the conical head of the pin. The disk collar has circular holes around its center.

Abstract: An apparatus is provided for manufacturing a fiber reinforced elastic sheet by extruding and processing an elastomer containing staples by 25 volume % or less. The apparatus includes a flow adjustment portion provided in a flow path direction of the elastomer for insuring a uniform flow of the elastomer in a sheet width direction. A weir portion is provided on the downstream side of the flow adjustment portion. A clearance Wo of an outlet in the vertical direction of the sheet, a clearance Wi formed by the weir portion in the vertical direction of the sheet and a distance l between the weir portion and the outlet have the relationship ofWo/Wi.gtoreq.2l.gtoreq.3Wo0.3 mm.ltoreq.Wi.ltoreq.5 MMin order to uniformly orient the staples along the thickness of the sheet.

Abstract: The invention relates to a hollow body made of fluoro resin, especially of PTFE, obtained by paste extrusion, exhibiting an anisotropy ratio lower than 1 and substantially equal to 0.5. For the manufacture of such hollow bodies a fluoro resin powder, especially unsintered PTFE, is mixed with lubricant, the mixture is compressed to obtain an isotropic compact tubular preform, the preform is introduced into an extrusion press, the preform is expelled through a passage of small cross-section of a die so as to form lengthwise-oriented fibers, the fibers are compressed at the exit of the passage in an internal expansion chamber of enlarged cross-section, so as to orient the fibers transversely, and the fibers are expelled through the exit orifice of the die to obtain a hollow body.

Abstract: A method for manufacturing plastic pipe such that the pipe has apertures formed therein when the pipe is viewed in cross-section, comprising the steps of having hot plastic flow through a die and subsequently be extruded through a die head to form an extruded wall component having first and second end wails, with the die head having formed therein a plurality of first sized gaps and a plurality of second sized gaps, with the second sized gaps having an aperture located inside each of said second sized gaps. The die is secured to a manifold assembly, with the manifold assembly comprising sets of tubes located centrally of one another, each set of tubes comprising a water inlet tube, a tube through which a vacuum is pulled, and a water return tube. Each set of tubes is positioned longitudinally within a respective die manifold tube with the outermost surface of each set of tubes spaced a first distance from the respective die manifold tube. Each of the respective die manifold tubes extends through the die.

Abstract: An in-line tubing die for forming thin walled plastic tubing from molten plastic extrudate is provided. The hub of the tubing die is concentrically positioned within a housing and held in place by radially extending fins that join the housing to the hub. Every one of the fins that holds the hub within the housing has an air passage formed through it so that the fins are of a uniform temperature and the plastic extrudate flows uniformly around each of the fins to keep the thickness of the plastic tubing walls uniform around the entire circumference of the tubing. An annular groove or grooves are provided around the housing and are enclosed by a sheath which permits the air to circulate around the housing and be warmed to some extent before entering the passages within the fins and thereafter entering into the passage extending coaxially with the hub and into the interior of the plastic tubing.

Abstract: Upstream of a distributor at which flow from an actuator is fed to the shaping orifices for the production of plastic extrusions and downstream of the extruder producing the stream of plastified plastic, a rotary adapter having a displacement body subdividing its cross section into asymmetrical partial cross sections is provided so that, upon deviation of a property of the extrusions from a desired value, the adapter can be rotated to compensate.

Abstract: Method and apparatus for the extrusion of tubing, sheets and profile shapes, wherein shearing strains in the material being extruded through a die serve to orient the microstructures of the material so that its strength properties are improved in the direction transverse to the extruding direction.

Abstract: An improved pipe production line is provided having an improved manifold assembly component and an improved former component.

Abstract: A method and an apparatus for the orientation of a plastic pipe, wherein a pipe blank (2) is produced with an extruder and fed into a pipe forming apparatus provided with movable moulds (3), such as a corrugator, the pipe being conveyed forward in the corrugator with said moulds over a mandrel (4), along which the pipe is further conveyed out from the corrugator. In accordance with the invention, the plastic pipe (7) is oriented radially immediately after the corrugator by means of a conically widening mandrel (5) forming an extension of said corrugator. The invention also relates to an oriented ribbed plastic pipe produced by the method.

Abstract: For the production of extrudates such as profiles or granules, pulverulent or finely divided ultra-high molecular weight polyethylene is processed on single screw extruders. By the use of a screw with a specific geometry, thermal degradation of the polymer into low molecular weight products is avoided. Furthermore, profiles are obtained which have perfect surfaces, are free of voids and pores, and have no internal stresses.

Abstract: Porous pipe formed of particles of vulcanized rubber dispersed in a binder resin such as polyethylene are stabilized to reduce degradation by ultraviolet light by dispersing in the binder resin an effective amount of an ultraviolet stabilizer such as 0.1 to 10% by weight of carbon black.

Abstract: A surface fastener engaging member manufacturing method includes: extruding from an extrusion nozzle a predetermined width of molten resin; introducing the molten resin into a predetermined gap between the extrusion nozzle and a die wheel to fill up coupling element molding cavities with the molten resin as the die wheel rotates in one direction; continuously molding a multiplicity of coupling elements integrally on the front surface of a continuous board-shaped base layer as the die wheel is rotated; applying a porous backing material to the base layer under pressure while the base layer is moved in response to the rotation of the die wheel; cooling the die wheel to a predetermined temperature; and positively pulling the base layer with the backing material attached thereto as cooled, from the die wheel as the molded coupling elements of the engaging section are removed off the coupling element molding cavities.

Abstract: An apparatus for extruding a powdered material forms an elongated pellet. The extrusion apparatus includes a connection mechanism arranged between the inlet and the constriction passages for continuously connecting two successively charged portions of the powdered material when the powdered material is repeatedly charged. By this mechanism, the formerly charged and semicompacted portion of the powdered material and the border surface upon the subsequent portion are broken, either by a core piece or a modified die cavity, whereby the portions of the powdered material are merged with each other before the constriction.

Abstract: A method and tool are provided for forming a patterned gasket bead on a surface. The tool includes a first portion which has a first recess that defines a first recess surface, and a mateable second portion having a second recess defining a second recess surface. The tool also includes a gasket material flow path that has a chamber section, and that is formed by the first and second recess surfaces of the first and second portions mated together. The tool further includes a gasket patterning member that is mounted within the chamber section of the gasket material flow path. The patterning member as mounted within the chamber section defines, with the first and second recess surfaces, a patterned extrusion opening through a discharge end of the first and second portions for extruding a patterned flow of gasket material.

Abstract: In order to achieve a good mounted state by itself without using other members such as spacers or stabilizers, an enlarged section, which is made by enlarging the inner wall of the hollow portion, is provided in the hollow of the hollow portion having the same contour shape throughout the entire length of the hollow extrudate. Thus, the regions such as the corners of the hollow portion are reinforced by said enlarged section to achieve required rigidity, i.e., position-retaining property.

Abstract: Apparatus for the manufacture of an ultra-high molecular weight polyethylene thin-wall pipe which is uniform in thickness and free from a folded mark. The ultra-high molecular weight polyethylene thin-wall pipe is manufactured by supplying ultra-high molecular weight polyethylene into and melting and kneading, continuously extruding the molten substance of the ultra-high molecular weight polyethylene from a die connected to a screw of the screw extruder to form a cylindrical roughly shaped article, and diametrically expanding the cylindrical roughly extruded article by a tapered core and taking up.

Abstract: The present invention includes a method of producing a reinforced extrusion product, the product of the method, and the apparatus for making a reinforced extrusion product. The method of producing an extruded composite of the present invention, comprises the general steps of: (a) extruding a longitudinally oriented composite precursor comprising: (1) at least one thermoplastic polymeric material and (2) a core mixture of at least one thermosetting resin and at least one filler material; whereby the thermoplastic polymeric material(s) is/are extruded so as to substantially enclose a space, and whereby the core mixture is disposed in the space; and (b) maintaining the composite precursor under conditions whereby the thermoplastic polymeric material(s) become(s) cooled and the thermosetting resin(s) become(s) cured so as to form the extruded composite of the present invention. The present invention also includes an extruded composite made in accordance with the method of the present invention.

Abstract: An apparatus for forming a chamber member which receives optical light waveguides comprises an extruder head for extruding the chamber member followed by a calibrating device which inserts members into each of the chambers to insure the desired dimensions of each of the chambers and a method of using the apparatus by extruding a chamber member, allowing the extruded chamber member to cool and then calibrating the dimension of the chamber walls of the chambers.

Abstract: An apparatus for manufacturing from a mouldable material a pipe having ribs on its outer surface and a smooth inner surface has a core including a shaft, a conically widening mandrel located downstream of the shaft in a direction of production and a kernel having an initial zone and an end zone respectively of substantially uniform diameters successively disposed downstream of the mandrel. An extrusion sleeve surrounds the core and forms with the core a nozzle for the material. The extrusion sleeve has a first end face located upstream of the kernel. Moulds encase the extrusion sleeve and the core, the moulds being movable along endless paths and having grooves on inner surfaces for forming the ribs on the pipe. A heater heats the initial zone of the kernel, the initial zone of the kernel being cylindrical. A first cooler cools the end zone of the kernel.

Abstract: An extrusion head for sheathing elongate objects such as cables has a housing with an elongate bore in which there is a hollow mandrel through which is passed the object to be sheathed. At the discharge end of the mandrel there is a forming tool made up of an annular forming tool part on the mandrel and a concentric forming tool part at the adjacent end of the bore of the housing. An extruder connected to the extrusion head housing forces sheathing material into the bore of the housing and out through the forming tool to form a sheath on the cable or other object as it is passed through the hollow mandrel. A rotor which is rotatable on the mandrel has a screw thread web of decreasing height for propelling sheathing material toward the forming tool. There are lubricated radial seals between the rotor, mandrel and housing. For applying a double layer sheath, there are two entrusion heads interconnected one behind another and supplied with sheathing material by two extruders.

Abstract: Fibre-reinforced tubes made of a thermoplastics material are manufactured using a method of extruding thermoplastics material in a drawplate with a diverging end zone, the end zone of which has a diverging annular flow space which has a ratio A.sub.s /A.sub.e between the exit area and entry area of at least 1.2, and a ratio between the length 1 of the lower edge of the annular exit space of the diverging zone and the width e of the straight section of said annular space which is less than 5; the extrusion operation being carried out in the presence of a liquid lubricant which is incompatible with said thermoplastics material at extrusion temperatures, said lubricant being present at the level of the external wall and at the level of the internal wall of said flow space. Tubes which are manufactured by way of this method are particularly resistant to a high degree of bursting and have an improved surface quality.

Abstract: Coextrusion apparatus for forming tubular elastomeric ply made up of first, second and third concentric streams of elastomeric material and a pair of coaxial helical patterns of individual reinforcing elements wound in opposite direction with respect to each other contained within the first and third streams of elastomeric material and separated by the second stream of elastomeric material. A pair of reinforcing element guides are rotatably mounted within the apparatus between stationary flow channels for the three streams of elastomeric material, and are rotated in opposite directions with respect to each other. The two helical patterns of reinforcing elements and three streams of elastomeric material merge together substantially simultaneously in concentric circles which lie in a plane generally perpendicular to a central axis of the coextrusion apparatus to form the tubular ply. A method for producing such a reinforced tubular elastomeric ply also is presented.

Abstract: An dome-shaped extrusion die for use in forming honeycomb monolith structures is disclosed. The die is formed by deforming an extrusion die having a flat cross section to obtain a dome-shaped cross section. Alternatively, the die may be fabricated from sinterable ceramic or metal powders in which case the holes and slots may be formed either in the green state, or in a chalk-hard state after partial densification.

Abstract: An extrusion head for a blow molding machine wherein a movable plunger is slidably mounted in a distributor head which receives a melt at an inlet end of its channel and directs it along such channel to the terminal end of the channel while simultaneously directing portions of it along spiral radial paths to the lower circumferential edge of the distributor head to fill an accumulator chamber which also causes the plunger to recede facilitating the filling of the accumulator chamber. The channel as defined by the adjacent circumferential wall and the curvilinear contour on the distributor head defines a smooth integral flow channel that is curvilinear in cross section.

Abstract: In the production of moldings from thermotropic, liquid-crystalline plastics, the chains of the LC polymer molecules are oriented in at least two preferred directions independent of one another. For this purpose, the polymer melt stream which emerges from an extruder is divided into two part streams which are fed via melt lines to an adapter. A distributing element which is caused to rotate by a drive unit is located in the adapter. The adapter is upstream of a slot die and is connected to the latter. One part stream forms a polymer matrix while the other part stream incorporates in, or is superimposed on, this polymer matrix individual polymer strands at different cross-sectional levels by the rotating distributing element. These polymer strands reinforce the polymer matrix. These polymer strands form multiple-pitch helices. The two part streams combined in the adapter enter the slot die and are shaped in the latter to give a multilayer melt film which is extruded through the slot die onto a cooling roller.

Abstract: A blow molding die includes a housing, and a mandrel with a core integrated therewith, combined to form a vertically extending annular melt passage communicating with a hole formed at its top portion for feeding a plasticized resin melt from an extruder, and terminating at die lips formed at its free bottom end. The mandrel has a pair or grooves symmetrical relative to its axis, formed at its peripheral surface so as to have hanger type profiles in its front developed view, and connecting to each other at lower ends thereof. The feed hole opens to the symmetrical hanger type grooves at top and central points thereof. Each groove has an arced surface and a cross-sectional area decreasing in a direction from the top and central point to the lower end.

Abstract: A large-diameter plastic pipe is made by extruding from an extruding-nozzle assembly a hollow thermoplastic strip having an outer rectangular cross section and formed with longitudinally extending outer walls and webs having inner surfaces and defining a plurality of longitudinally extending internal cells separated by the webs from one another. Substantially only the inner surfaces of the outer walls and the cell-forming webs are then cooled to size the strip and provide it with a predetermined compressive strength stable up to a predetermined critical pressure of the design strength while externally shielding external surfaces of the strip and thereby preventing cooling of same.

Abstract: The invention relates to the kind of die which has many helical grooves (40) spiralling around a mandrel, and to a new way of feeding the liquid resin from the main supply duct (48) to the grooves. Instead of the usual one groove to one conduit relationship, in the invention the channels (41) to the grooves are intercalated with the conduits (47). Each groove is fed via feed-channels (45,46) from two of the conduits, and each conduit feeds two of the grooves. The result is that the cooler liquid resin from the walls of the main duct is constrained to move to the centre of the stream in the groove. The arrangement leads to an improvement In the homogeneity of the resulting film.

Abstract: A mechanism for forming plastic board including a base, a chamber and a passage formed in the base, a pump disposed in the chamber, a housing disposed above the base and including a passage for supplying plastic materials to the chamber, a pathway formed in the base and communicated with the chamber, two mold disposed in the base, in which one is located above the pathway and the other one below the pathway, the mold cavities being communicated with the pathway such that the plastic materials may flow into the mold cavities via the pathway so as to form the plastic board.

Abstract: This invention is directed to a lubricating arrangement for a plastic extruder (1) for production of cylindrical plastic tubes with a smooth inner surface. The plastic extruder (1) includes a mandrel which consists of a die core (6) which is a cylindrical coaxial extension of an extruder screw (2). Die core (6) rotates together with said screw, and a stationary external die member (7). The lubricating arrangement is located in the external die portion for lubricating its forming surface. The lubricating arrangement has a plurality of radially directed plugs (11, 11', 17, 17'), each plug engaged in a bore (10) in the external die member. The inner end of the plug lies in the die surface. Lubricating ducts (13) are provided to the bore which are connected with a source of a lubricant, which supplies a lubricant under pressure.

Abstract: An apparatus (10) is disclosed for simultaneously forming two dough sheets from a single cooker extruder (12), with the dough sheets each being formed by a plurality of dough ropes which are guided by guide posts (44) at equally spaced intervals on a conveyor (16) for passing between the pressing rollers (42) of a sheeting device (18). Specifically, the die (24) attached to the die head (20) of the cooker extruder (12) includes a roof-shaped extension formed by first and second die plates (26) interconnected by their front edges at an obtuse angle. Top and bottom pates (28) are interconnected to the top and bottom edges of the die plates (26). The back edges of the die plates (26) and of the top and bottom plates (28) are interconnected to an annular connection plate (30) which is attached to the die head (20) by bolts (34) passing through counterbored bores (32) in the connection plate (30) and threaded into the die head (20).

Abstract: An extrusion method for obtaining a long phenolic resin pipe having excellent heat resistance by using an extruder having a screw, a cylinder, a die and a mandrel, the mandrel being inserted into a through-hole formed in the screw along the screw axis and protruding into the die along the screw axis, the die satisfying the following formulasR.sub.1 /R.sub.2 =0.25.about.1.0S.sub.1 /S.sub.2 =0.1.about.2.5where R.sub.1 is an outside diameter of the die flow path at the die outlet, S.sub.1 is a cross-sectional area of the die flow path at the die outlet, R.sub.2 is an outside diameter of the die flow path at the die inlet, and S.sub.2 is a cross-sectional area of the die flow path at the die inlet, and the inclination of the outer periphery of the die flow path portion from the die inlet to a starting point of the uniform flow path portion having the same cross section as the die outlet is not larger than 35.degree.