Abstract: The present invention discloses an extrusion die module having a flat compression seal and a conical or otherwise angled spillover surface. The die module promotes a flat surface to flat surface compression seal outside of the flow distribution channels and promotes better streamlined flow and material combination than a traditional flat disk die module. The die module promotes a reduced overall diameter and wetted diameter in comparison to standard flat disk dies. Further, the present invention relates to a method for utilizing an extrusion die module with a conical or otherwise angled spillover surface to minimize the die surface area wetted by an intermediate layer in a multi-layer coextrusion process.

Abstract: The present invention discloses an extrusion die module having a flat compression seal surrounding a conical or otherwise angled spillover surface. The die module promotes a flat surface to flat surface compression seal outside of the flow distribution channels and promotes better streamlined flow and material combination than a traditional flat disk die module. The die module promotes a reduced overall diameter and wetted diameter in comparison to standard flat disk dies. In addition, the conical or angled spillover surface is surrounded by the planar sealing surface. Further, the present invention relates to a method for utilizing an extrusion die module with a conical or otherwise angled spillover surface to minimize the die surface area wetted by an intermediate layer in a multi-layer coextrusion process.

Abstract: The present invention discloses an extrusion die module having a flat compression seal surrounded by a conical or otherwise angled spillover surface. The die module promotes a flat surface to flat surface compression seal outside of the flow distribution channels and promotes better streamlined flow and material combination than a traditional flat disk die module. The die module promotes a reduced overall diameter and wetted diameter in comparison to standard flat disk dies. In addition, the present invention relates to an extrusion die module having a spillover surface surrounding a planar sealing surface. Further, the present invention relates to a method for utilizing an extrusion die module with a conical or otherwise angled spillover surface to minimize the die surface area wetted by an intermediate layer in a multi-layer coextrusion process.

Abstract: The present invention relates to an extrusion die assembly. Specifically, the present invention relates to an extrusion die assembly comprising a pair of extrusion dies wherein one extrusion die is disposed within the second extrusion die. The extrusion dies may comprise a plurality of extrusion die modules wherein at least one of the extrusion die modules incorporates a flat compression deal with a conical or otherwise angled spillover surface. Further, the present invention relates to a method for utilizing an extrusion die assembly comprising a pair of extrusion dies, each having at least one extrusion die module having a conical or otherwise angled spillover surface.

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

Abstract: Proposed is a device for continuously producing seamless plastic tubes, wherein provided as a distributor element for the molten material to be fed to an annular gap is a distributor plate which is arranged within the cross-section of the mold cavity and in which the molten plastic material is passed to the peripheral surface of the distributor plate substantially radially with respect to the direction of production by way of distribution passages which branch tree-like, wherein the flow path of the molten plastic material is the same in each of the individual distribution passages between the entry opening and the peripheral surface

Abstract: The invention relates to an extrusion head for the manufacture of tubes comprising at least one layer of expanded plastic by extruding a stream of molten plastic containing a blowing agent through an annular passage cross section made in the extrusion head and in which the stream of molten plastic containing the blowing agent spreads out circumferentially and welds itself to itself by the recombining of the two stream fronts, the said extrusion head being equipped with a special-purpose thermal regulation device allowing the molten plastic containing the blowing agent to be heated or cooled after the stream fronts have recombined.

Abstract: A device for extruding and blow-molding thermoplastic tubular components with an extrusion head. The head has a central stem which is perforated in an axial direction. A distribution body lies radially around the stem so as to radially distribute the stream of thermoplastic material. An annular extrusion port is arranged downstream. The invention allows to avoid stagnations of material and to easily adapt the device to various types of thermoplastic material.

Abstract: An extruder arrangement for viscous material, especially rubber or natural or synthetic rubber mixtures, is provided. It has a screw extruder (12) with an extruder screw (16) that in the direction of conveying is followed downstream by a conveying device. The conveying device is a planetary pump (18), the outer ring (22) of which is rotatably supported.

Abstract: There is provided an extrusion head that is capable of largely increasing a production speed rather than a conventional head that extrudes supplies a high viscous melt-coating composition.

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

Abstract: An annular die designed to produce polymer foam using only one or more ambient gasses as a blowing agent includes an exiting channel with an exit having a cross-sectional area between about two and about ten times that of a smallest point within the exit channel. The section of the die from the smallest point to the exit is thermally isolated from the rest of the die, and the temperature thereof is independently controlled. In addition, the interior surface of the exit channel is coated with a friction-reducing coating.

Abstract: An extrusion die for a hollow member includes: a male die for defining a plurality of hollow portions of the hollow member, the male die including an annular base portion and a bridge portion bridging the annular base portion; a female die for defining an outer peripheral portion of the hollow member, the female die being fitted in the annular base portion; and a mandrel having a plurality of forming protrusions, the mandrel being inserted and held in a mandrel holding slit formed in a center of the bridge portion in a fore-and-aft direction. The mandrel includes a mandrel main portion divided into a plurality of divided members and a plurality of rigid pins each arranged in a fore-and-aft direction of the mandrel main portion, and wherein the rigid pins are pinched by and between the divided members of the mandrel main portion with tip portions of the rigid pins protruding from an front end of the mandrel main portion, whereby the tip portions constitute the forming protrusions.

Abstract: An extrusion method and an extruder, the material to be extruded being fed with a material feeding device (1) into a radial pump unit included in the equipment. The radial pump unit comprises conical gearwheels (2) which are adjacently positioned and rotate in opposite directions. The radial pump unit transfers the material in an annular flow into the extruder's nozzle (4). Additional material (20) can be supplied into the product through the radial pump unit.

Abstract: An extruder die head comprises an internal cylindrical mandrel and a shell, which encloses said mandrel concentrically. Between said mandrel and shell an annular channel is formed that empties into the die slit. A polymer melt is fed through a line to the annular channel. To prevent the polymer melt in the area of the start of the annular channel from penetrating into a slit that forms between the mandrel and the shell due to heat expansion, there is between both mandrel and shell a ring with such a coefficient of thermal expansion that when heated up due to the polymer melt said ring seals the slit between the shell and the mandrel.

Abstract: Disclosed is a method of sizing nonderivatized extruded cellulosic tubes by the use of a mandrel structure that includes a hollow sizing portion having openings which gather gas bubbles that may evolve at the interface between the extruded tube and the sizing portion and allows the gas to pass into the hollow interior of the mandrel. The mandrel contains a sizing portion larger than the extruded tube, which allows for improved sizing of nonderivatized extruded tubes that are used as casings.

Abstract: A method and apparatus are described for coextruding two materials A and B, in which B is extruded on A through a port (3), in which the separating wall between the flows of A and B is formed as a flap closure (4) adapted to act as a non-return valve for the flow of B into A, and further means are provided for extruding B through the port in pulses. The pulses may be effected by opening and closing the closure, by mechanical transmission means or by the effect of imposing pressure difference on the flap (4) by the flows of A and/or B. The pulsing means preferably involves rams (1). The invention is particularly suitable for extruding a low viscosity material B onto a higher viscosity material A, or for making sheets or pipes with alternating segments of differential flexibility, or for coextruding a flow of solid particles with a flow of liquid.

Abstract: A process for forming an end cap in an extruded ceramic tube. An end cap forming cavity of an end cap forming die is positioned so that, when the body of the end cap forming die is situated against an extrusion die, ceramic material is able to be forced into the end cap forming cavity, through a passageway communicating between the end cap forming cavity and a backfill reservoir, and into the backfill reservoir. A plunger projects into the backfill reservoir to force the ceramic material from the backfill reservoir back through the passageway and into the end cap forming cavity to compact the ceramic material so that the ceramic material within the end cap will be provided with a substantially uniform density.

Abstract: The present invention provides an apparatus and method for manufacturing polymeric thin-walled tubular members, which are well-suited for use as vascular grafts. The apparatus of the present invention enables extrusion of a tubular member having an extremely thin wall thickness so as to facilitate passage through tortuous vascular passageways. The apparatus achieves uniform wall thickness in a tubular member by establishing and maintaining axial alignment of a ram having a concentrically disposed guide rod therein with a die supported in concentric relation to the guide rod.

Abstract: The invention relates to a method and an arrangement for cooling an extruded hollow product. According to the invention, the extruder (1) is provided with means for sucking air through the pipe (2). The air to be sucked is thus in contact with the inner surface of the pipe (2), cooling the pipe from the inside. Therefore the cooling of the pipe (2) can be realized in an efficient and simple manner. By arranging the sucking to occur from the middle of the conical extruder (1), no weld line will be formed in the extruded product, and the extruder (1) can be cooled effectively from the inside. According to the invention, the heat contained by the air that has been sucked through the pipe (2) can also be utilized.

Abstract: Apparatus and a method for extruding a honeycomb, providing correction in bowing of the extruded honeycomb structure, employs a deflector device having a base plate including an aperture aligned in a direction parallel to the extrusion axis through which the plastic material is conveyed to the die, the aperture having a varying diameter; and, a slide plate movably mounted to the base plate, the deflector device positioned upstream of the extrusion die, the degree of bow reduction depending on the diameter or width of the aperture imparting a pressure drop gradient on the flow stream entering the die.

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

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

Abstract: An extrusion head for use in the paste extrusion of lubricated PTFE fine powder, the extrusion head comprising an external die having an inlet, a chamber, and an outlet, a tip positioned in the chamber of the die, the tip having a circumferential ridge formed therein that extends into the chamber, the chamber having a shape complementary to the ridge so as to form a space between the external die and the tip to allow lubricated PTFE fine powder to pass therethrough, and a mandrel which extends through the external die and supports the tip in the chamber.

Abstract: There is provided a weather strip for an automobile, wherein a void due to a gas pocket is prevented from occurring to a boundary part between a core bar and a slightly foamed solid rubber portion, and a continuous extrusion molding system for molding the same. The weather strip for the automobile comprises a U-shaped trim formed by embedding the core bar in the slightly foamed solid rubber portion, foamed so as to have a specific gravity of 0.8 to 1.2, and tiny holes having a depth reaching the core bar are defined in part of the slightly foamed solid rubber portion in such a way as to be arranged in line along the longitudinal direction of the weather strip.

Abstract: A die apparatus, a method of using the die apparatus to produce co-extruded polymeric articles, and co-extruded polymeric articles produced using the die apparatus and method are disclosed. The die apparatus includes a hollow vane configured to extrude a material into a chamber within the die, thereby producing a co-extruded web. The co-extruded web has a plurality of distinct, discontinuous phases in the cross-web direction, the phases having a uniform width as shown by a coefficient of variation of less than 8 percent for any three consecutive phases. The phases are substantially continuous down-web and are surrounded by a matrix having two or more layers.

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

Abstract: Provided is a blown molding die to obtain a film having excellent properties and good appearance in blown film forming of a thermoplastic resin manifesting anisotropy in molten state. The blow molding die has a simple structure compared with a conventional spider die, and can be produced easily and at low cost.

Abstract: An extrusion molding method including plasticizing and kneading a raw material (1), composed of a synthetic resin material having high heat-resistance and strength, extruding the material from a molding die (3) to form a tubular body (51), passing the tubular body (51) on a sizing die (4) to give it a final inner diameter, cooling and hardening the tubular body (51). The molding die (3) and sizing die (4) are coupled to each other by a connecting pipe (6). The sizing die (4) is made of a carbon material. A first air (81) is supplied to an interior of the sizing die (4) through the connecting pipe (6). A second air (92) is supplied to an interior of the molding die (3) so that an air lubrication layer is formed between an inner surface (52) of the continuous product (5) and an outer surface (41) of the sizing die (4).

Abstract: The present invention is directed to a method and apparatus for using a spiral flow assembly in a polymer extrusion process to make small diameter tubing for such items as wires, cables, and tubing. The invention comprises a mandrel inside of a housing, the mandrel having spiral grooves located on its external surface. A polymer melt is introduced into the housing through an ingress port and flows into and through the spiral grooves on the outside surface of the mandrel, in what is called “groove flow” or “channel flow.” As the polymer melt flows through the grooves or channels, the housing and mandrel begin to separate by either having the housing taper outwardly, becoming gradually larger in diameter along the axial distance of the mandrel or having the mandrel begin to taper inwardly, becoming gradually smaller in diameter along the axial distance of the mandrel.

Abstract: An extruder die head, preferably a blown film head, has an internal cylindrical mandrel and a cylindrical jacket, which envelops concentrically the mandrel. Between the mandrel and jacket an annular channel is formed that empties into a die slit. At least one melt-supplying line empties into the annular channel in the area opposite the die slit. To avoid slits between the central mandrel and the jacket, enveloping the mandrel, where the polymer melt can accumulate and deposit, the mandrel is made as one piece with a flange-like foot and is provided in the area, adjacent to the foot, with at least one borehole, which feeds in the melt. On the mandrel adjacent to the foot is shrunk a ring, which seals the slit between both the mandrel and jacket. The cylindrical jacket is mounted above and connected sealingly to the shrunk-on ring to form the annular channel.

Abstract: A honeycomb structure molding die that can mold a thin-walled honeycomb structure without degrading the moldability has been provided. A honeycomb structure molding die 8 comprises at least supply holes 81 to supply materials and slit grooves 82 that are communicated with the supply holes 81 and mold the materials into a honeycomb shape, wherein the groove width of the slit grooves 82 is not more than 100 &mgr;m and simultaneously, recesses 41 and protrusions 42 that extend in the direction in which the materials are extruded are provided on a pair of opposing side surfaces 820 of the slit grooves 82.

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: An automatic slug feeding device for delivering slugs to a compression mold for molding golf ball cores is characterized by synchronized rotary transfer, slug conveyance, gripping mechanism transfer and a tray conveyor for transferring slugs from an extruder to a mold loading robotic arm, and subsequently to a mold press. The rotary transfer device receives slugs from the extruder and the slug conveyor linearly conveys individual slugs from the transfer device. The gripping mechanism simultaneously removes a plurality of slugs from the conveyor and deposits them in an array of receptacles in a molding trays which are shuttled to an unload position, where the mold loading robotic arm transfers slugs into a mold press. Storage of extruded slugs prior to compression molding is thus eliminated, cycle time is reduced, core quality is improved, and operator safety is maximized.

Abstract: An annular die designed to produce polymer foam using only one or more ambient gasses as a blowing agent includes an exiting channel with an exit having a cross-sectional area between about two and about ten times that of a smallest point within the exit channel. The section of the die from the smallest point to the exit is thermally isolated from the rest of the die, and the temperature thereof is independently controlled. In addition, the interior surface of the exit channel is coated with a friction-reducing coating.

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: Disclosed is a mandrel structure for extruding a tube composed of a non derivatized cellulose. The mandrel includes a hollow sizing portion having openings which gather gas bubbles that may evolve at the interface between the extruded tube and the sizing portion and allows the gas to pass into the hollow interior of the mandrel.

Abstract: The present invention provides a hollow ceramic monolithic support that has high isostatic strength, a method of manufacturing the hollow ceramic monolithic support at low cost, and a molding die therefor.

Abstract: The invention relates to an extrusion die assembly having a balanced flow path in which the die and tip modules cooperate to form an extended exit channel which communicates with an extrusion channel. The die is rotatably mounted on the die holder and the tip module is rotatably mounted within the axial bore. Each of the rotatably mounted components is independently driven by a motor. The motors are controlled to provide an infinite variation in relative rotational motion between the rotating components.

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

Abstract: A tube with a thin thickness or a thin tube made of a synthetic resin material having high heat-resistance and high strength (for example, PEI material, PEEK material or the like) is produced by means of extrusion molding. An extrusion molding method forms a continuous product (5) for a thin tube by plasticizing and kneading a raw material (1) composed of a synthetic resin material having high heat-resistance and high strength by means of an extrusion molding machine (2), extruding the plasticized and kneaded raw material from a molding die (3) to form a tubular body (51) having a circular cross section, further passing the tubular body (51) on a sizing die (4) to give a final inner diameter to the tubular body (51), cooling and hardening the tubular body (51). The molding die (3) and sizing die (4) are coupled to each other by a connecting pipe (6). The sizing die (4) is made of a carbon material. A first air (81) is supplied to an interior of the sizing die (4) through the connecting pipe (6).

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

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

Abstract: Molten resin material is continuously extruded from an extruding hole including a plurality of engaging-element-molding portions disposed with a constant pitch in a width direction of an extruding nozzle and a substrate-molding portion with which lower ends of the engaging-element-molding portions communicate. An ascending/descending member disposed at a front face of the extruding nozzle and made of a laterally long plank ascends and descends to vertically open and close the extruding hole of the extruding nozzle. As a result of such continuous molding, a surface fastener is continuously molded in which each of plurality engaging elements has stem and an engaging extruding head projecting at least toward one side from an end of the stem standing on a surface of a flat substrate. The engaging element thus molded has a thickness, in a direction perpendicular to a projecting direction of the engaging head, gradually increasing from a top portion of the engaging head to a base end of the stem.

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

Abstract: An extrusion head for blow molding extruded plastic containers, with a ring gap nozzle having a mandrel and a ring-shaped nozzle body having an elastically deformable sleeve, and setting devices for radially deforming the elastic sleeve. The sleeve defines a nozzle gap, the width of which is variable by axially movement of the mandrel and/or of the nozzle body. The geometry of the gap can be changed by deforming the sleeve in the course of extrusion of a hose-like, pre-shaped blank. The sleeve is axially supported in the nozzle body, and/or on the mandrel only on segment-like surfaces.

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.