Abstract: An injection molding apparatus includes an injection molding nozzle having a nozzle body defining a channel for flow of molding material and a nozzle tip coupled to the nozzle body. The nozzle tip is shaped to define a converging gap with a mold component into which the nozzle tip is inserted during use. A seal piece having a wedge or wedge-like portion is disposed between the nozzle tip and the mold component Pressure of molding material acting on a surface of the wedge portion wedges the wedge portion into the converging gap.

Abstract: A nozzle adapter for an injection molding machine includes a body and one or more retainers mountable to an outer surface of the body. When the body and a retainer are assembled together they cooperate to define a cavity adapted to contain a cartridge heater between the body and the retainer. Access to allow replacement of the cartridge heater can be gained by removing the retainer from the body without removing the entire nozzle adapter from the injection molding machine.

Abstract: A nozzle for an injection molding apparatus is provided. The injection molding apparatus has a mold component that defines a mold cavity and a gate into the mold cavity. The nozzle includes a nozzle body, a heater, a tip, a tip surrounding piece and a mold component contacting piece. The nozzle body defines a nozzle body melt passage therethrough, that is adapted to receive melt from a melt source. The heater is thermally connected to the nozzle body for heating melt in the nozzle body. The tip defines a tip melt passage therethrough, that is downstream from the nozzle body melt passage, and that is adapted to be upstream from the gate. The tip surrounding piece is removably connected with respect to said nozzle body. The mold component contacting piece is connected with respect to the nozzle body.

Abstract: A valve gate of an injection valve includes a center pin whose end portion is exposed to a cavity, a valve main body accommodating the center pin, a valve tip surrounding an outer circumferential portion of the end portion of the center pin and fixed at an inner circumferential portion of the valve main body, a sleeve pin provided so as to be slidable along the center pin, a reservoir portion formed between the valve main body and the sleeve pin and accommodating a molten resin, and a heater surrounding the reservoir portion, wherein the sleeve pin is displaceable between a position where an opened state is established and a position where a closed state is established, and an end portion of the heater facing the cavity is positioned closer to the cavity than an end portion of the reservoir portion facing the cavity when the closed state is established.

Abstract: Disclosed is a safety connector (100; 200; 300) for a hot runner (600) having a valve stem (104) and an actuation assembly (102), the safety connector (100) including: a shear member (106) releasably interlocking the valve stem (104) with the actuation assembly (102), once the shear member (106) has interlocked the valve stem (104) with the actuation assembly (102), the valve stem (104) becomes movable in response to movement of the actuation assembly (102), and the shear member (106) being configured to shear destructively, and responsive to a predetermined undesired force acting on the shear member (106), the shear member (106) shears and the valve stem (104) becomes released from the actuation assembly (102).

Abstract: A system for producing blow molded articles. The system includes an injector nozzle mounted to a parison cavity block having a parison cavity such that the injector nozzle injects molten plastic into the parison cavity to form a parison. The injector nozzle is mounted to the parison block by means of two seats, a distal seat where the distal end of the injector nozzle is seated within an opening in the parison cavity block and a proximal seat, a linear distance inwardly from the distal seat, where a circular flange on the injector nozzle is seated within an annular shelf formed in the parison block. The two spaced apart seats ensure an accurate alignment between the centerline of the injector nozzle and the parison cavity. As a further feature, there is a system to heat the nozzle tip to reduce the temperature differential between the nozzle and the parison cavity.

Abstract: Disclosed, amongst other things, is a gate insert of an injection mold that includes a base member. The base member defines a nozzle interface for receiving, in use, a nozzle of a melt distribution system that is heated, in use, by a heater, and a gate, the gate configured to fluidly link, in use, a melt channel of the nozzle with a molding cavity. The gate insert further includes a thermal regulator associated with the base member, the thermal regulator includes a direct energy conversion device that is capable of heating and cooling, wherein the thermal regulator is controllably operable, in use, to control the temperature of the gate.

Abstract: The invention relates to a process for producing plastic components, in particular optical lenses or optical light-guides, wherein plastic melt is injected via a sprue (3, 4, 6, 8) into a cavity (1) of a moulding tool shaping the component and additional plastic melt is after-pressed into the cavity (1) for the purpose of compensating a volume contraction of the injected plastic melt due to cooling. The process is characterised in that the plastic melt located in the sprue (3, 4, 6, 8) is kept flowable by means of energy introduced in the region of the sprue until such time as the molten core of the plastic component has solidified in the course of the after-pressing of plastic melt for the purpose of compensating the volume contraction due to cooling (holding-pressure). The invention further relates to an apparatus for implementing the process.

Abstract: Provided is an injection mold which can reduce the amount of resin that is separated from injection-molded parts and then thrown away. The injection mold includes for an embodiment an extension cylinder coupled to an upper clamp plate and having a nozzle at an end thereof; a nozzle positioner disposed under the nozzle, the nozzle positioner having a nozzle insertion groove adapted to receive the nozzle; a gate-lock-pin holder disposed under the extension cylinder and the nozzle positioner, comprising a gate lock pin which has a first end coupled to a gate molded part and a second end coupled to the gate-lock-pin holder, and adapted to separate the gate molded part from an injection-molded part; a gate stripper plate disposed under the gate-lock-pin holder and adapted to separate the gate molded part from the nozzle; and a cavity plate and a core plate disposed under the gate stripper plate and having a cavity which is shaped like the injection-molded part.

Abstract: A hot runner (10) is provided including a canal (11) and a heat-shrinkable tube (12) covering on the canal (11). The heat-shrinkable tube (12) can shrink along the canal (12)'s contour when heated. The present invention further provides a mold (20) using the hot runner.

Abstract: A co-injection process is provided for fabricating improved multi-layer containers, including but not limited to blood collection tubes, evacuated blood collection tubes, culture bottles, centrifuges tubes, and syringe barrels. The container includes a tube (10) having a bottom wall (12) and a side wall (14) with an open end (18). The container can be provided with a stopper having an upper portion (22) and a skirt with an outside portion (30), a well (34) and a cavity (36). The tube and stopper assembly can be used for medical purposes including containing a blood sample within an enclosed interior space (40).

Abstract: A nozzle body defines an upstream channel. A downstream bracing portion has a lateral bore. A nozzle tip extends laterally through the lateral bore of the bracing portion and has a sealing surface for engaging a gate component that defines a mold gate. The runnerless nozzle further includes a securing component inserted into the bracing portion to hold the nozzle tip against the bracing portion. The bracing portion or the securing component defines a lateral channel in communication with the upstream channel for delivering molding material to the nozzle tip. The nozzle tip can be removed by removing the securing component.

Abstract: A stringing preventing member is provided and includes: a member having an opening portion through which resin injected from an injection nozzle of an injection molding apparatus is fed to a mold including a fixed mold and a movable mold; and a projection portion protruding inwardly with respect to an opening of the injection nozzle, so as to define at least a part of a contour of the opening portion. A ratio of an effective opening area of the opening portion to a surface area of an inner wall surface of the opening portion contacting with the resin at an inside of the opening potion is 0.6 or less, and a ratio of the effective opening area of the opening portion to an area of the opening of the injection nozzle is 0.6 or more.

Abstract: A nozzle for an injection molding apparatus is provided. The injection molding apparatus has a mold component that defines a mold cavity and a gate into the mold cavity. The nozzle includes a nozzle body, a heater, a tip, a tip retainer, and a nozzle seal piece. The nozzle body defines a nozzle body melt passage therethrough that is adapted to receive melt from a melt source. The heater is thermally connected to the nozzle body for heating melt in the nozzle body. The tip defines a tip melt passage therethrough that is downstream from the nozzle body melt passage, and that is adapted to be upstream from the gate. The tip retainer is removably connected with respect to the nozzle body. The nozzle seal piece is connected with respect to the nozzle body. The material of nozzle seal piece has a thermal conductivity that is less than at least one of the thermal conductivity of the material of the tip and the thermal conductivity of the material of the tip retainer.

Abstract: Disclosed, according to an aspect of the present invention, is a molding system that includes a mechanical fuse assembly configured to (i) abut a conduit connection, and (ii) permit movement of a conduit connection.

Abstract: An injection molding hot runner nozzle and a method of making such a nozzle are disclosed that improves heat transfer along the length of the nozzle. The nozzle includes a nozzle body and a heating element located on an outer surface of the nozzle body having a form-fitting thermally conductive shroud that conforms to a profile of the nozzle and the heating element.

Abstract: The mold includes a first molding cavity connected to a first hot channel for supplying a primary molding material, a second overmolding cavity connected to a second hot channel for supplying an overmolding material; and a core configured to be first introduced in the first cavity for a molding operation of a first layer, and to then be introduced, with the first layer thereon, in the second cavity for an overmolding operation of a second layer. At least one supporting member is arranged to support the core with respect to the first cavity during the entire molding operation of the first layer. An opening left in the first layer by the supporting member is filled and/or covered by the second layer.

Abstract: Disclosed is a nozzle tip, having a tip insert attached to a nozzle tip outlet end of a nozzle tip body, the tip insert being made of a material, or having a thermal barrier coating, having a thermal conductivity value of K<10 W/m ° K, and having a lower thermal conductivity than that of the nozzle tip body, to preclude the conduction of excessive heat to the nozzle tip outlet end, and promoting a more decisive fracture of the solidified resin at a gate orifice upon ejection of a molded product, thereby eliminating a string of molten resin and a vestige of excessive height, both of which are undesirable, on the molded product.

Abstract: A screed mold method for continuously or periodically molding thermoplastic material into a cushioning element is disclosed.

Abstract: A hot runner nozzle system (500) comprising a nozzle tip (100) adjacent to a nozzle (405) in series, and a retainer (400) adjoining both the nozzle tip (100) and the nozzle (405) in parallel, the retainer (400) having a first retainer thread (435), for connection to a nozzle thread (420) to form a first seal (450) between the nozzle end (440) of the retainer (400) and a nozzle shoulder (430), a second retainer thread (460), for connection to a tip thread (455) to form a second seal (470) between the inlet end (475) of the nozzle tip (100) and the gate end (425) of the nozzle (405), a seal ring (115) for creating a gate seal (496) with a gate insert (120), and a plurality of flats (410) thereon to facilitate torquing of the retainer (400) to the nozzle (405), the torque value applied to the retainer (400) being about two to four times of that applied to the nozzle tip (100) to facilitate removal of the nozzle tip (100) independent of the retainer (400).

Abstract: Method for sealing interfaces within an injection mold having a first surface and a second surface includes structure and/or steps whereby an active material actuator configured to be disposed in a manner suitable for generating a force between the first surface and the second surface. The active material actuator is configured to generate a force in response to sense signals from a transmission structure. Methods are also provided for centering a nozzle tip within a gate opening, and adjusting tip height of a nozzle tip with respect to a gate opening, also using active material inserts.

Abstract: A nozzle for an injection molding machine is disclosed that allows for smooth, blended melt flow into a mold cavity. The nozzle includes a nozzle body with a nozzle melt channel in fluid communication with a manifold melt channel and a nozzle tip. The nozzle tip includes a first melt channel in fluid communication with the nozzle melt channel and a plurality of second melt channels between the first melt channel and an annular melt channel. The annular melt channel is formed between a sealing device and the nozzle tip.

Abstract: Disclosed is a hot-runner nozzle system, including: (i) a nozzle housing being configured to convey a molten molding material, (ii) a sieve being coupled with the nozzle housing, (iii) a nozzle tip being securely coupled relative to the sieve, and (iv) a retainer securely extending from the sieve, the retainer connecting with the nozzle tip.

Abstract: A two stage spring pack device comprising a nozzle or back up insulator, surrounded by a first stage spring for applying an initial force, and a plurality of Belleville springs to exert a secondary force against a thermally expanding hot runner manifold in an injection molding system, precludes resin leakage between a manifold and nozzle or between mating manifolds in a cross manifold system. The first stage spring imparts a relatively low initial force against the hot runner components while the system heats up from ambient temperature to prevent plate bowing and component hobbing, until it is fully compressed, at which point a subsequently larger sealing force is exerted by the constant force Belleville springs to prevent leakage between the mating components at operating temperature and injection pressure.

Abstract: An improved nozzle for high melt pressure applications includes an inner body portion having a melt channel, the inner body portion having an inlet face and a melt outlet; an outer body portion having a seal face, with the outer body portion inducing a compressive force on the inner body portion at least during operation of the nozzle; the plane of the inlet face of the inner body portion intersecting the outer body portion, resulting in no part of the inner body portion extending beyond the seal face of the outer body portion; and the inner and outer body portions having different relative thermal conduction and expansion coefficients.

Abstract: A method is provided for the formation of a molded article comprising the steps of: providing at least one liquid plastisol composition, providing an injection molding apparatus including an injection barrel, feeding the at least one liquid plastisol composition to the injection barrel, heating the at least one plastisol composition within the injection barrel to the fusion temperature of the plastisol, and injecting the at least one plastisol composition to the mold.

Abstract: An injection molding system and injection molding method for making molded parts that include one or more planar heaters having a thin or a thick film resistive heater element coupled, secured, or releaseably secured to one or more sides of each of the one or more injection molding nozzles. The releasably secure coupling allows heater device to be visually inspected, tested, removed, and/or replaced. The planar heater device can have a support device patterned with a film electrical resistive path. The electrical resistive path can include any pitch or number of electrical resistance lines, such that a longitudinal uniform heat profile is generated along a melt flow channel of the one or more injection molding nozzles when the nozzles are in use. In some examples, the planar heater has more than one film resistive heater element that can be coupled to one or each side of a nozzle, with dielectric material interposed between the planar film resistive heater elements.

Abstract: A nozzle system is provided for an injection molding machine. The nozzle system includes a nozzle tip that is removably connected to a nozzle body with a sealing and mounting sleeve element. The nozzle body includes a first connector for releasably connecting with a second connector defined on the sleeve. The sleeve element further includes an alignment bearing for engaging a bearing surface defined on the nozzle body for precisely locating the nozzle tip within the nozzle body along on a predetermined axis. Further embodiments of the invention provide a valve pin disposed in the nozzle body and nozzle tip. The valve pin includes a bearing surface for engaging a guiding surface defined on the second melt channel for aligning the end of the valve pin with a mold gate. Further embodiments also provide an integrally connected nozzle tip and sleeve element.

Abstract: The invention relates to a method and to a device for controlling/regulating the distribution of the injection molding compound in multi-cavity injection molds, especially for molds with a large number of cavities, for example 48 to 128 cavities. The invention distributes the injection molding compound in groups of, for example, four to twelve nozzles. Each group is provided with one classical nozzle, as the master nozzle, that is controlled via the local heating capacity and temperature sensors. All other nozzles or cavities of the same group are configured as slave nozzles that have no temperature sensors. The virtual actual temperatures are computed via saved model computations and are displayed on the user panel. The user is thus provided with the desired/actual temperature values for every nozzle and can thus influence every single nozzle, depending on the result, in the form of temperature values.

Abstract: The present invention is a nozzle for an injection molding runner system where parts of the nozzle, and in particular the nozzle tip are made from a nanocrystalline material. Nanocrystalline materials used include nanocrystalline copper and nanocrystalline nickel, which have high thermal conductivity and increased material strength. A conventional form of the metal is worked till its grains are reduced in size to less than 100 nm to achieve the desired properties.

Abstract: An improved nozzle apparatus and method of manufacture are provided in which non-compatible components (such as a metallurgically non-weld-compatible nozzle tip and seal) may be secured/attached. For example, the apparatus and method may comprise securing a seal between a first portion of a nozzle tip and a retention ring. The retention ring may comprise a material that is weld-compatible with the nozzle tip and may be welded to the nozzle tip whereas the seal may be non-compatible with the nozzle tip. As a result, the materials of the nozzle tip and the seal may be chosen substantially without regard to their compatibility.

Abstract: The invention provides an injection molding nozzle or nozzle segment having a recessed terminal or terminal housing such that the radial profile of the nozzle or nozzle segment is reduced. Components of the nozzle or nozzle segment and injection molding apparatus having the nozzle or nozzle segment are also part of the invention.

Abstract: A drop tip is provided for conveying injection molding material from a molding material supply into a mold. The drop tip has a body including an internal bore and a drop passage extending from the internal bore. The internal bore has an arcuate lower end terminating in a gate to prevent retention of molten material therein.

Abstract: An apparatus and process for fusing labels onto plastic parts having multiple contoirs and/or holes during the molding process is presented. According to the invention, a label having art work or wording on its interior surface and made of the same material as the plastic piece to which it is to be applied, is positioned onto a mold. Placement is accomplished through the use of a robotic arm having an insulated plate at its operational end to eliminate electrical charge transfer to the tool. The interior side of the label is insulated. An electrical charge is then applied to the front surface of the label enabling it to be positioned and held in place on an irregularly shaped mold. In the preferred embodiment, polypropylene is used for the label and the plastic layer.

Abstract: An artificial nail is formed by injection molding a first section and a second section. The first section and second section are adjacent to one another. One of the sections defines a front distal tip of the artificial nail and is formed by injecting a quantity of heated material under pressure from a nozzle into a sprue, through a runner and through a cavity gate into a mold cavity. The other section is formed by injecting another quantity of heated material under pressure from a heated nozzle through another cavity gate into the mold cavity.

Abstract: A composite material component for an injection molding assembly includes a first portion formed of a precipitation hardened, high thermal conductivity material and a second portion formed of a precipitation hardened, high strength material, which are integrally joined together. The thermal conductivity of the high thermal conductivity material is greater than the thermal conductivity of the high strength material, and at least one strength aspect of the high strength material has a value greater than the corresponding value of the same strength aspect of the high thermal conductivity material. The high thermal conductivity material and the high strength material can be precipitation hardened together under the same precipitation hardening conditions to achieve increases in the value of at least one strength aspect of the high thermal conductivity material and the value of at least one strength aspect of the high strength material, relative to their respective unhardened conditions.

Abstract: A series of injection molding nozzle tips having a novel inner insert. The novel inner insert in accordance with the embodiments of the present invention includes a finned profile having flow channels between the finned sections. The finned profile and its associated flow channels cause the flow of molten plastic in the nozzle to go through a breakup into the flow channels before it is merged at the nozzle flow exit. This breaking up of the molten plastic flow and its merging insures a better mixing of the molten plastic and also reduces stresses within the molded part.

Abstract: An injection molding apparatus is disclosed that includes a manifold having at least one manifold melt channel therethrough, a mold plate defining a gate for transmitting melt flow to a mold cavity, and at least one nozzle including a nozzle body and nozzle tip defining a nozzle melt channel in communication with the manifold melt channel. The nozzle tip includes a substantially conical forward portion having a terminal end that is aligned with and spatially offset a predetermined distance “d” from the gate, the nozzle melt channel having a discharge opening that is located rearward of the terminal end for discharging melt flow from the nozzle melt channel towards the gate.

Abstract: A nozzle for an injection molding apparatus, including a nozzle body having a nozzle melt channel for receiving a melt stream from a manifold melt channel, and a collar mounted on the nozzle body. One of the nozzle body and the collar has a shoulder formed therein and the other of the nozzle body and collar has a radially disposed protrusion for engaging the shoulder to act against separation of the collar from the nozzle body.

Abstract: An injection molding hot runner nozzle includes a nozzle body comprising a nozzle core, a nozzle tip, and a melt passage extending through the nozzle body for conveying melt from a manifold through the nozzle tip and to a gate of a mold cavity. A cylindrical sleeve is disposed around the nozzle body, the sleeve being slidably removable from the nozzle body. A wire heating element for heating melt in the melt passage is is spirally wound about the sleeve. A temperature sensor comprising a wire is spirally wound about the sleeve.

Abstract: An injection molding apparatus including an injection manifold having a manifold melt channel, a mold plate having a mold bore, and a hot runner nozzle located in the mold bore and having a nozzle melt channel. A mold insert including a melt channel includes an upper end adjacent the nozzle, a first outer surface adjacent the upper end, and a lower portion including a second outer surface, wherein the second outer surface is in sealing contact with an inner surface of the mold plate. A mold gate insert retainer includes an inner surface surrounding the first outer surface of the mold gate insert and a threaded outer surface for mating with a threaded inner surface of the nozzle. The first outer surface of the mold gate insert and the inner surface of the mold gate insert retainer are non-threaded. A lower end surface of the mold gate insert may form a wall of the mold cavity and may be angled.

Abstract: A hollow heating cylinder for attachment to an injection nozzle for an injection molding system. An elongated heating cartridge is spirally wound on the outside of the cylinder. The heating cartridge contains two electrically heatable heat conductors which are electrically separated from one another and are located in different regions in the longitudinal direction of the heating cartridge. One heat conductor is positioned for heating the mouth region of the nozzle and the other heat conductor is positioned for heating the shank region of the nozzle.

Abstract: A series of injection molding nozzles, one series having a two-piece nozzle (for use with a conventional nozzle housing), another series having a three-piece nozzle (for use with a conventional nozzle housing), and yet another series having a two-piece nozzle (for use with modified nozzle housing). The two-piece nozzles include either a nozzle insert with a sealing surrounding piece portions (when used with a conventional nozzle housing), or an inner insert with an outer insert portions (when used with modified nozzle housings). The three-piece nozzles include an inner insert, an outer insert and a sealing surrounding piece portions. The modified nozzle housings include a press-fit frontal insert. The nozzles form multiple seals with the nozzle housing and reduce heat loss by unique geometric and material combinations.

Abstract: Tool insert for the initial cut of a hot-passage nozzle for an injection molding machine, which tool insert (10) accommodates the anterior (tool side) part of a nozzle and is insertable in turn in a suitably dimensioned recess (21) of the tool (20), which tool insert (10) consists of an anterior cylindrical fitted part (11) having a flow passage (11a) and a receiving head (12) for the tip of the nozzle. At least two cavities (chambers) (23) separated from each other are present between the outer wall (12a) of the receiving head (12) of the tool insert (10) and the wall of the recess (21) in the tool (20), one of which cavities (23) communicates with the supply passage (31) for a coolant, present in the tool, and the other cavity communicates with the discharge passage (32) for the coolant, present in the tool. Also, at least one flow connection is provided between the two cavities (23), preferably located as far as possible from the openings of the coolant passages (31, 32) in the tool.

Abstract: A collar for an injection molding apparatus includes an upstream end for maintaining a head of a hot runner nozzle in contact with an outlet surface of a manifold and a downstream end for abutting a mold plate. An inner surface of the collar contacts an outer surface of the nozzle in order to align a nozzle channel of the nozzle with a manifold channel outlet of the manifold. A noncircular ridge protrudes from the inner surface of the collar in order to reduce contact between the outer surface of the nozzle and the collar.

Abstract: The present invention is a hot runner nozzle design consisting of a nozzle core with slotted flange seated inside a slotted nozzle housing, a nozzle tip seated on the nozzle core, and a nozzle tip seal seated on the nozzle tip. Furthermore, the present invention is a quick assembly hot runner nozzle design. The present nozzle design provides for the easy installation and removal of the nozzle by means of turning and sliding the nozzle. This provides for easy installation or removal of the nozzle when servicing the mold in the machine and without the complete disassembly of the hot runner mold. The seal located on the nozzle tip seals the tip area to avoid plastic leakage. Positioning the seal closer to the gate area also contributes in increased nozzle tip mass thus resulting in a better heat distribution profile along the nozzle tip, and especially in the area closer to the gate.

Abstract: A modular hot runner nozzle having a variable length includes a first nozzle portion and a second nozzle portion provided in series between a manifold and a mold gate of an injection molding apparatus. The first nozzle portion and the second nozzle portion having respective nozzle channels for delivering the melt stream from the manifold to a mold cavity. A nozzle tip is provided at a forward end of the hot runner nozzle. The nozzle tip and the manifold are generally fixed within the injection molding apparatus so that axial thermal expansion is taken up by a telescoping or a slidable connection that is provided between the first nozzle portion and the second nozzle portion.

Abstract: The present invention provides an injection molding nozzle having a nozzle tip. The nozzle tip includes a body portion and a tip portion that extends from a forward end of the body portion. The tip and/or body portions may include at least one planar surface area on an outer surface thereof. The tip and/or body portions may also be provided with a convex and/or concave outer surface area. The geometry of the nozzle tip is such that it maximizes an outer surface area in order to increase the nozzle tip's heat conductance.

Abstract: A nozzle end is provided for removable mounting to a nozzle body for use in multiple-tipped molding applications such as edge-gated systems. The nozzle end is made of a highly thermally conductive material and is preferably inserted at least partially inside the forward end of the heated nozzle body. Removable nozzle tips are insertable in the front end of the nozzle end.

Abstract: An injection molding apparatus comprises a manifold having a manifold channel for receiving a melt stream of molten material under pressure and delivering the melt stream to a nozzle channel of a nozzle. A mold cavity receives the melt stream from the nozzle and the nozzle channel communicates with the mold cavity through a mold gate. A thermocouple is coupled to the mold core of the mold cavity in order to measure the temperature of the molten material in the mold cavity.