Abstract: Medical device balloons are formed from a tubular parison by a process or apparatus which establishes a controlled location (initiation zone) on the parison where radial expansion is initiated. Initiation within the initiation zone is achieved by heating the parison in that location to a higher temperature than the remainder of the parison for at least a portion of the blowing time. A variety of apparatus configurations are provided, some of which allow for the size and location of the initiation zone to be readily reconfigured. Balloons can also be modified, post-blowing, using heating apparatus and methods described.

Abstract: A dual constituent container includes a compartment for liquids and an elongate inwardly directed recess open to the container exterior and isolated from the compartment. The container is formed by blow molding, using a mold that incorporates a shaping feature projected longitudinally into the mold cavity. The shaping feature incorporates an arrangement of longitudinal channels having a channel width such that when a thermoplastic preform is expanded into contact with the mold cavity walls and the shaping feature, portions of the expanded preform span the channels and cooperate with the channels to provide passages that accommodate pressurized air to facilitate separation of the expanded preform from the shaping feature. The same portions of the expanded preform can partially protrude into the channels, thus to form longitudinal ribs along the recess which aid in frictionally holding a secondary constituent.

Abstract: A module for heating a plastic container perform, includes a longitudinal heating tunnel bounded transversely by the longitudinal vertical internal faces of two walls, one a heating wall, being equipped with a heating system, and the other wall having aeration orifices that are intended to let the air blown by a blower pass through them transversely from the upstream, and in which module a first portion of the preform is heated in the heating tunnel, while a second portion of the preform is held outside the heating tunnel through a longitudinal opening. The blower includes a deflector that deflects a portion of the air blown towards the second portion of the preform so as to prevent it from being heated up to its softening point, characterized in that the upstream end of the deflector is aerodynamically profiled.

Abstract: Disclosed herein is a mold and a method of using the mold. The mold includes a first mold half, a second mold half and a stripper assembly. The first mold half defines a first mold half molding structure. The first and second mold halves are openable and closable along a mold opening axis. The second mold half includes a first sub-assembly defining a first sub-assembly molding structure and a second sub-assembly defining a second sub-assembly molding structure. The first and second sub-assembly molding structures are each matable with the first mold half molding structure to define a mold cavity. The first and second sub-assemblies are at least partially independently movable along the mold opening axis. The stripper assembly includes first and second split inserts. The first and second split inserts are movable along a stripper assembly axis that is normal to the mold opening axis.

Abstract: Disclosed herein is a mold including a first mold half, a second mold half and a retainer plate. The first and second mold halves are configured to open and close. The first and second mold halves are configured to capture a molded part therebetween when closed. The retainer plate is positioned between the first and second mold halves and defines an aperture having a first aperture portion that is sized to prevent the pass-through of the molded part, and a second aperture portion that is sized to permit the pass-through of the molded part during opening of the first and second mold halves. The retainer plate is movable to control which of the first and second aperture portions is aligned with the molded part.

Abstract: A blow molding apparatus that includes a preform supplying station for supplying preforms in an upright state, a heating station for heating the preforms to a suitable temperature condition for blow-molding while transporting the preforms, a blow station for blowing the heated preforms to form blow-molded products, and a collection station for collecting the blow-molded products.

Abstract: A mold for a medical device balloon has a cavity adapted to receive a hollow parison expandable therein to form the balloon. The cavity has a cone region and a body region. The cone region is heated to a higher temperature, or the mold wall is formed to deliver applied heat more efficiently to the cone region, relative to the body region of the mold.

Abstract: The method for thermally conditioning preforms in accordance with the invention comprises the following steps:—Placing the preforms on a chain conveyor (2);—Conveying the preforms through a first thermal conditioning stage (1) and subjecting them to a first heating or cooling heat exchange;—Removing the preforms from the first thermal conditioning stage and holding them outside for a predetermined amount of time in order to redistribute the temperature inside the preforms;—Subjecting the preforms to at least a second heating or cooling heat exchange in a second thermal conditioning stage (1) or in the first thermal conditioning stage. The invention also concerns the plants for heating or cooling preforms in accordance with the above method.

Abstract: A system for direct injection of selected thermal-infrared (IR) wavelength radiation or energy into articles for a wide range of processing purposes is provided. These purposes may include heating, raising or maintaining the temperature of articles, or stimulating a target item in a range of different industrial, medical, consumer, or commercial circumstances. The system is especially applicable to operations that require or benefit from the ability to irradiate at specifically selected wavelengths or to pulse or inject the radiation. The system is particularly advantageous when functioning at higher speeds and in a non-contact environment with the target.

Abstract: The conditioning station of an injection stretch blow mold machine is provided with a heater ring for each hot, soft preform presented to the station. The heater ring emits infrared light waves that are confined to the transition region of the preform between the neck and main body portions to pin-point the addition of heat to the transition region.

Abstract: Tools of plastics processing machines are cooled over their surface and/or at particular points as soon as compound supply is finished. Heat is thus suitably withdrawn from the shaped compound, ensuring the fastest possible cooling and shortening cycle times. The invention relates to a closed, coolant-filled cooling system for tools of plastics processing machines having at least one compressor, a supply pipe, a tool region to be cooled and a discharge pipe, the supply pipe being connected to the outlet of the compressor and the discharge pipe being connected to the inlet of the compressor, while at least one open end of the supply pipe plunges into at least one bore arranged in the tool region to be cooled, and an open end of the discharge pipe is sealed to this bore. The supply pipe and the discharge pipe may be combined in a coaxial pipe with the supply pipe arranged in the centre and the discharge pipe enveloping the supply pipe.

Abstract: The method and the device serve for the blow moulding of containers (2). Preforms (1) of a thermoplastic material are heated in the region of a heating path (24) and then transferred to a blowing device (25). The blowing device (25) is provided with at least one blowing station (3) for moulding the preforms (1) into the containers. The preforms (1) are retained along at least a section of the transport path thereof by a support element (46) which is at least partly loosely introduced into a mouth section (21) of the preform (1) and tightened in the mouth section (21) after the introduction thereof.

Abstract: A process and a device for the manufacture of a hollow body, particularly of a heat-resistant hollow body, which is molded out of a heated preform of thermoplastic plastic in a contoured blow mold through the introduction of a first medium into the preform, which medium is stored in a first medium storage unit and is under a pressure (p1) (preblowing phase), and the more or less simultaneous stretching of the hollow body through a stretching rod and the introduction of a second medium in the hollow body, which medium is stored in a second medium storage unit and the pressure of which (p2) is higher than the pressure of the first medium (p1) (final blowing phase), and which is cooled by a third medium, which is medium stored in a third medium storage unit (rinsing phase), whereby the preblowing medium is under a pressure of approximately 2-20 bar, the final blowing medium is under a pressure of approximately 15-45 bar, and the cooling medium is under a pressure of approximately 30-45 bar.

Abstract: Heat is extracted from compressed gas used in a blow-molding process by expansion cooling the exhausted gas and/or passing the exhausted gas through a vortex tube, which supplies cold gas at an exit thereof. The cold gas is then routed through cooling channels in the mold. This obviates the need for recirculating or externally chilling a coolant and saves energy.

Abstract: A molding apparatus and method for creating a molded object that incorporate a mold with a mold cavity, a mold core disposed within the mold cavity, and a reciprocating sleeve insertable between the mold core and the mold cavity. The apparatus and method include injecting molten plastic between the core and the sleeve forming a preform object, then retracting the sleeve and expanding the preform object by blow molding, using pressurized fluid provided through jets in the mold core, until the object expands to fill the mold cavity. The apparatus and method further include thermal conditioning of the sleeve when it is retracted to create a temperature profile in the sleeve that is then applied to the preform object, thereby providing finer control of the temperature profile of the preform object before the final blow molding step.

Abstract: A process of controlling the thickness profile of a blown tubular film, consisting of thermoplastic plastics, around the circumference of same when producing blown film by means of blown film extruders, having a film extrusion die, wherein a measuring device measures the film thickness of the tubular film around the circumference and wherein a control device variably controls the cooling gas flow as a function of the measured film thicknesses around the circumference in sectors, wherein cooling gas flows are supplied from the outside in the direction of production in two separate planes, and wherein the cooling gas flows are controlled variably and in circumferential sectors around the circumference in the two planes in respect of their physical parameters.

Abstract: The invention provides a cooling system for cooling a rotary mount (2) comprising two rings (4, 7) capable of rotating relative to each other, each ring having a raceway, the mount further comprising a bearing device constituted by rolling bodies interposed between the two raceways, the cooling system being characterized in that it comprises at least one circuit for passing a cooling fluid, which circuit is pressed against one of the two rings (4, 7) of said mount. It also provides a rotary mount including such a system, and a machine, in particular a blow-molding machine, including such a mount.

Abstract: The present invention refers to an arrangement for the production of blow-molded hollow bodies from plastic with a blow molding machine, wherein a cooling medium can be blown via a conduit into a blow mold respectively into the hollow body for blowing up and cooling of the blow-molded hollow body. For improvement of cooling the interior of the hollow body within the blow mold, a closed conduit system is provided, in which the cooling medium circulates and is kept at an elevated pressure level and is cooled by means of a heat exchanger. Thereby, a higher yield of piece per time is realized at lower production cost. The closed cooling medium circulation system can be essentially retrofitted to all blow molding machine in order to raise efficiency.

Abstract: A method of making a catheter balloon, and a balloon formed thereby, in which a polymeric tube is radially expanded in a mold having a wall with an outer surface and an inner surface defining a chamber, and having at least a section with one or more channels in the wall. The channels result in improved transfer of heat to the polymeric tube within the chamber of the mold during blow molding of the tube to form a balloon, so that the tube is heated more quickly and evenly. One aspect of the invention is directed to a balloon having sections with improved thin walls.

Abstract: A cooling system for cooling sleeves (2) fixed to a carrier plate (1), by means of a fluid which is passed from a fluid inlet (15) to a fluid outlet (22) by way of fluid conduits (7, 14, 10, 11, 21) supported by means of the carrier plate (1). The fluid conduits (7, 14, 10, 11, 21) include main supply conduits (7) and supply conduits (10, 11) which extend approximately transversely with respect to each other. The supply conduits extend in a mutually parallel relationship and are arranged in pairs in the carrier plate (1) and are connected to a row of sleeves (2) by way of intake (16) and discharge conduits (17). The row of sleeves (2) is so disposed between the supply conduits (10, 11) of a pair such that each sleeve (2) is connected to both supply conduits (10, 11), and fluid communication is interrupted (plug 24) in at least the one supply conduit (10) of the pair substantially at the middle of its longitudinal extent (l).

Abstract: Disclosed, amongst other things, is: (i) a mold-cooling device; (ii) a molding system having a mold-cooling device; (iii) a mold assembly having a mold-cooling device; (iv) a molded article made by a molding system in cooperation with a mold assembly and with a mold-cooling device; and (v) a method of a mold-cooling device.

Abstract: A cooling tube assembly for operating on a malleable molded plastic part. The cooling tube assembly comprising a porous tube/insert having a profiled inner conditioning surface, and a vacuum structure configured to cooperate with the porous tube. In use, the vacuum develops a reduced pressure adjacent the inner conditioning surface to cause an outer surface of the malleable molded plastic part, locatable within the cooling tube assembly, to contact the inner conditioning surface of the porous insert so as to allow a substantial portion of the outer surface of the malleable part, upon cooling, to attain a profile substantially corresponding to the profile of the inner conditioning surface. The cooling tube assembly having a simplified cooling structure that includes a cooling channel configured on the porous insert, the surface of which include a surface treatment for a sealing thereof to substantially avoid a leakage of coolant therethrough.

Abstract: A device for carrying a preform in a temperature condition oven, including a gripping device provided with gripping claws, which enclose an outer surface of the neck of the preform. An inner core is provided that penetrates axially inside the neck over a distance substantially equal to the axial length of the neck, such that it presents a lower transverse surface. When the preform is in place on the gripping device, it is substantially axially placed at the boundary between the neck and the body of the preform.

Abstract: A system and method for superplastic forming a workpiece. The system includes a superplastic forming cell formed of a plurality of individual stations or modules, each one performing a specific manufacturing step or process on the workpiece. Individual stations include a preheat station, a forming station, a cooling station, a cleaning station and a trimming station. These stations work in conjunction with one another to reduce superplastic forming cycle times and correspondingly increased production times when manufacturing a workpiece using a superplastic forming process.

Abstract: A mold assembly for blow molding comprises first and second mating mold components, each mating mold component comprising molding surfaces open to a mating face of the mold component and defining the exterior of an article to be molded from a tubular parison and at least one replaceable element being attached thereto by retaining means accessible from the mating face thereof whereby the replaceable elements may be installed and removed while the mating mold component is mounted in a press of a blow molding machine. The replaceable elements comprise any of inserts comprising molding surfaces defining a neck portion of an article to be molded, a blow needle to pierce the wall of and pressurize the parison and heat pipes for transferring heat from the molding surfaces. A blow molding machine comprises a press mechanism for operating a mold assembly and a mold assembly according to the invention mounted thereto.

Abstract: Medical device balloons are formed from a tubular parison by a process or apparatus which establishes a controlled location (initiation zone) on the parison where radial expansion is initiated. Initiation within the initiation zone is achieved by heating the parison in that location to a higher temperature than the remainder of the parison for at least a portion of the blowing time. A variety of apparatus configurations are provided, some of which allow for the size and location of the initiation zone to be readily reconfigured. Balloons can also be modified, post-blowing, using heating apparatus and methods described.

Abstract: An intimate fit preform cooling tube with an inner mating surface that includes a polymeric coating to increase its lubricity and thereby reduce friction with a preform to be engaged therewith. The cooling tube of the present invention substantially reduces or eliminates preform ovality and gate stretching problems.

Abstract: A cooling device and method useful for reducing the total injection molding cycle time of an injection molded tube, and more particularly to applying cooling to areas of a preform that are not in direct contact with the water cooled inside surface of a take out tube.

Abstract: A stretch blow molding system that condition preforms such that the temperature distribution within the cross-section of each preform is optimized prior to blow molding operations is provided. The system has a temperature measurement and control system capable of directly monitoring both the outside as well as inside surface temperature of preforms at different stages of transport throughout the thermal conditioning section of the system.

Abstract: Fluid flow grooves (11) with a flat cross section being formed between the back surface of a metal mold (2) for blow molding and a back-up member (4) which adheres tightly to this back surface. A plurality of these fluid flow grooves (11) are provided, and these fluid flow grooves are disposed densely in parallel with partition walls (21) interposed between the grooves. Fluid inlets (12) and outlets (13) are formed in the respective fluid flow grooves (11). A heating fluid or cooling fluid enters the respective fluid flow grooves (11) via the inlets (12) from a fluid supply manifold (14). The fluid flows out of the outlets (13), enters a fluid discharge manifold (15), and is discharged to the outside. Rapid heating and rapid cooling of the metal mold (2) are performed, no irregularity occurs in temperature, and the cycle time can be shortened, so that a metal mold device for blow molding in which the energy consumption is small can be obtained.

Abstract: A device (1) for cooling and/or thermal conditioning of hot preforms or parisons (6), in particular of parisons for the production of blow-moulded bottles made of plastic material, limits and/or reduces the deformations of said parisons during cooling by containing the transverse deformations of the end close to the opening (8) of the parison. The device is provided with a tubular portion of prolongation which wraps totally around the parison that rests on its internal surface with one of its sections (9). Described herein is the corresponding method for cooling the parison (6).

Abstract: An apparatus and method for blow molding an article having a concave base wherein a mold has a base component comprising a molding surface for forming at least a portion of the concave base and a path for conduction of heat transfer fluid through channels within the base component. Improved heat transfer is effected in the base component by locating the channels at a plurality of distinct depths therein.

Abstract: A blow molding method includes steps of moving a split mold to a parison receiving position where a parison is supplied and receiving a parison, closing the split mold, performing blow molding at a blow molding position, and opening the split mold at a product discharge position and thereby discharging a product. The method further includes steps of: sequentially reciprocating each split mold in trains of split molds provided opposed to each other across the parison receiving position to and from a position opposed to the parison receiving position; and sequentially reciprocating the split mold disposed at the position where the split mold is opposed to the parsion receiving position to and from the parison receiving position for performing blow molding. There is also provided a blow molding apparatus for carrying out this blow molding method.

Abstract: A device for heating parisons made of a thermoplastic material and having a supporting ring for blow molding hollow bodies, having a conveyor means, a plurality of holding means which are arranged on the conveyor means and grip the head area of the parisons between the supporting ring and the mouth and radiant heaters arranged on the path of movement of the parisons carried by the holding means, a shield supported by the conveying means being assigned to each holding mandrel in the form of a cover plate which is located at the height of the supporting ring and has a borehole to receive the supporting ring. Furthermore, there is also a cooling device, which acts directly on the exposed head area. This permits optimum protection of the head area of the parisons, which is not to be shaped or deformed, to prevent unacceptable heating.

Abstract: The device serves for the blow molding of containers that comprise a thermoplastic material, wherein the device has at least one blowing station with at least one blow mold. The blow mold is formed from at least two blow mold segments that are supported by supports, wherein the blow mold has a base extension. The base extension is arranged in such a way that it is capable of being positioned in the direction of a longitudinal axis of the blow mold, and is supported by a base plate. The base plate connects the base extension to a positioning device. The base plate is additionally connected to the base extension by a profiled coupling section, wherein this profiled coupling section is formed from a coupling element, which is connected to the base plate, along with a counter element that is connected to the base extension. The profiled coupling section is capable of being actuated via a manual lever.

Abstract: A base assembly used as a part of a mold assembly for forming a container has a base insert and a flow divider plate that co-operate to define a continuous fluid passageway for cooling or heating the base insert. The flow divider plate has an upper surface portion having at least one raised runway extending in a first pattern covering a substantial area of the upper surface portion. The base insert has a lower surface portion with a continuous channel extending in a second pattern. The channel is positioned adjacent the at least one raised runway in sealing relation therewith to define a continuous fluid passageway.

Abstract: In a biaxial stretch blow molding apparatus (10) for wide-mouthed containers, preforms (6) that are in an inverted state are conveyed on a single plane by preform carriers (40) that go around a carrier circuit (30) in the form of a loop, are heated via a heating station (60), and are then transferred via a transfer station (80) to stretch blow molding mold assemblies (72) that go around a circular looped path (71). The molded wide-mouthed containers (1) are taken out of the stretch blow molding mold assemblies (72) along a conveying path on a same plane and collected by a collection station (90). Wide-mouthed containers can be formed continuously and at high speed, which is less wasteful and more economical than the case where wide-mouthed containers that are formed from films.

Abstract: The present invention relates to an improved method and apparatus for injection molding and cooling molded articles such as preforms so as to avoid crystallinity. The apparatus and method make use of a take-off plate for removing articles from a mold, which plate may include heat transfer devices for cooling exterior surfaces of the molded articles or preforms, and a system for cooling in a controlled manner interior surfaces of the molded articles or preforms.

Abstract: Method and apparatus for cooling molded plastic pieces preferably includes a take out structure/step configured to hold the plurality of plastic parts oriented such that closed ends thereof are disposed toward an inside of the take out structure and open ends thereof are disposed toward an outside of the take out structure. A movement structure/step is configured to cause relative movement between the take out structure and at least one of a first cooling station and a second cooling station. The first cooling station includes a first cooling structure/step configured to provide a cooling fluid to an inside of the plurality of plastic parts through the open ends thereof. The second cooling station includes a second cooling structure/step configured to provide a cooling fluid to an inside of the plurality of plastic parts through the open ends thereof.

Abstract: An injection-molding machine cooling tube, which cools molded plastic parts, includes a porous cooling tube having an outer surface and an inner surface. Preferably, the porous cooling tube has a porosity in the range of 3-20 microns. A cooling fluid passageway is preferably disposed adjacent the porous cooling tube outer surface and is configured to carry a cooling fluid to extract heat from the porous cooling tube. Fluid flow structure, preferably a vacuum, is configured to cause a molded plastic part inside the porous cooling tube to expand into contact with at least a portion of the inner surface of the porous cooling tube.

Abstract: A mold assembly for forming a container has two modular mold half shells that are adapted to be surrounded by mold half carriers. Each modular mold half shell has an upper body mold section and at least one lower body mold section. The upper body mold sections of the mold half shells are releasably secured in vertical registry with the mold half carriers. The upper body mold sections have upper inner walls defining an upper cavity whose shape corresponds to an upper portion of the container to be formed. The modular mold half shell have at least one lower body mold section and preferably multiple interchangeable lower body mold sections that are releasably secured with the upper body mold section. The lower body mold sections have lower inner walls defining a lower cavity whose shape corresponds to a lower portion of the container to be formed.

Abstract: A method and apparatus for handling preforms from an injection molding machine whereby an array of molded articles received from the mold is reconfigured into a single row to assist in downstream auxiliary processing.

Abstract: A method of extrusion blow molding is disclosed; the method allows the finished part to have consistent and even wall thickness within a broad range of local mold radii. This result is achieved without resorting to injection blow molding or other common techniques of deforming the parison.

Abstract: A hot fill hot fill mold assembly has two mold half shells and two mold half carriers for supporting the mold half shells. The shells each have an inner wall that defines the shape of at least a portion of the container to be formed. Each shell has outer wall surface portions and a plurality of spaced apart slotted grooves extending between the outer wall surface portions that define open air spaces recessed from the outer wall portions. The mold half carriers have a carrier inner wall that overlays in contacting and thermal conducting relation the outer wall surface portions of a corresponding one of the mold half shells and overlays the spaced apart slotted grooves to create thermal buffering open air pockets between the mold half shells and the mold half carriers so as to reduce the thermal conduction away from the mold face and improve hot fill container formation.

Abstract: A mold is provided for use with a wheel-type blow mold machine, the mold being one of a plurality of molds for locating in a circular pattern on a wheel of the blow-mold machine and having a longitudinal direction for aligning tangentially with a circumferential direction of the mold wheel and a transverse direction perpendicular to the longitudinal direction. The mold has a first part and a second part. The first part has a first molding portion with a longitudinal end in the longitudinal direction of the mold and a first end portion adjoining the first molding portion at the longitudinal end of the first molding portion and having a free edge opposite the first molding portion, the free edge being non-parallel to the longitudinal direction and the transverse direction. The first part also has an outer cooling circuit located in the first end portion, and an inner cooling circuit located in the first end portion at a different location in the transverse direction than the outer cooling circuit.

Abstract: A housing is mounted to a slide that transports a series of preforms downward under the influence of gravity through a pre-heating apparatus toward a reheat blow molding machine. The housing is coupled to the slide so that a selected portion of each of the series of preforms is shielded from the general enviroment, and heating elements and directing elements are fixed within the housing so that heat from the heating elements is directed toward the selected portion of each series of preforms as the preforms desend down the slide to achieve a persistent thermal gradient in the preforms prior to the re-heating and blow-molding of the preform.

Abstract: A PET hot fill bottle (2) has a neck (3) and a body (4). It is stretched and blown into a cavity (14), with internal pressure holding the body against the cavity. During a first period, the cavity is heated to 100° to 160° C. for between 3 to 7 seconds to relax stresses in the body. During a second period the cavity is cooled to 60° to 120° C. for 4 to 8 seconds. This solidifies it—without introducing stresses—so that it can be removed from the mould. The resulting bottle is heat stable when filled with water close to its boiling point, namely at 92° C. to 98° C. For the rapid heating and cooling of the mould cavity, it is provided with two series of passages (16, 17). The former house ohmic heaters (18); whilst the latter are connected to water and air supply lines (19, 20).

Abstract: In an injection stretch blow molding method, at least one injection molded preform is transferred from a preform molding section to a blow molding section by way of a transfer section and the at least one preform is blow molded into at least one container in the blow molding section. In the preform molding section the at least one preform is injection molded in an upright state with an open neck section thereof facing upward. In the transfer section, the at least one upright preform is turned upside-down and transferred to the blow molding section in an inverted state. Then, the blow molding section blow molds at least one container from the at least one inverted preform.

Abstract: A simplified perform handling device including an end-effector arranged to substantially conform, in use, to an end portion of a preform and to seal therewith. The device also includes an aligning jig to align the preform with the end-effector. The device provides improved preform thermal and angular orientation characteristics when used in a transfer apparatus of an injection blow molding system, or simplified end-of-arm tool for two-stage preform production. The device may also be operated to condition a preform retained on the injection mold core plate assembly of an injection mold.

Abstract: An air cooled or heated blow mold is shown having a mold cavity shell and a mold holder. The mold cavity shell is made by a process of nickel vapour deposition and so requires no hand finishing or polishing. The mold cavity shell has a cavity portion with a front face defining a cavity in the shape of a portion of a product to be molded. The mold holder is located rearwardly of the mold cavity shell and defines an inner wall spaced from the mold cavity shell cavity portion to define a heat transfer passage between the inner wall and the cavity portion. In use, air is passed through the heat transfer passage to transfer heat to or from the mold cavity shell.