Abstract: An injection unit for injecting plastic into a cavity of a mold includes an injecting device connectable between an extrusion die and the mold. The injecting device includes a mouth having a plurality of openings that is insertable into the mold so that the plastic flows through the plural holes into the mold. A drive is connectable to at least a portion of the injecting device for rotating the mouth portion and the plural opening of the injecting device about a central axis as the plastic flows through the holes into the mold.

Abstract: The object of the invention is to provide a method for molding a resin-molded article having an excellent surface appearance without any resin-intrusion part on the front surface of a skin thereof. In the invention, the skin is placed on a part of a inner wall of a mold and then injecting a synthetic resin into a cavity of the mold to effect an integral molding of a resin-molded article having the skin on a part thereof, wherein a mold having a first gate on a first inner wall part located on the part other than the back surface of the skin placed on the inner wall of said mold and a second gate on a second inner wall part which faces the back surface of the skin placed on the inner wall is employed; and wherein the synthetic resin is first injected from said first gate until the tip portion of the synthetic resin comes close to the edge of said skin, and then the synthetic resin is injected from the second gate.

Abstract: A single piece battery jaw and method and apparatus for producing the same employs a stack molding type machine with material injection from the platens. The apparatus can effectively injection mold a one-piece jar with a straight side wall or an undercut side wall. Zero draft capability is also provided. The apparatus also includes an extraction device and core stabilizers.

Abstract: The invention intends to provide a method of manufacturing an optical disc capable of efficiently manufacturing a high quality optical disc by a consecutive product line, and to improve productivity in an injection molding step. The method is constituted by bonding two disc halves wherein a first disc half storing information therein and molded by a mold of a first injection molding unit and second disc half storing information therein, which information is different from that stored in the first disc half, and molded by a mold of a second injection molding unit are paired with and bonded to each other.

Abstract: A plastic part having a complex structure as a first layer and a simple structure as a second layer, is formed using a method for molding. Initially, a single mold is provided, the mold having an interior cavity and a runner reaching from an exterior of the mold to the cavity. The mold is kept closed while a quantity of a first plastic material is injected via the runner into the interior cavity to form a first layer of the plastic part. The mold is then partially opened, creating an increased interior cavity section, into which a quantity of a second plastic material is injected, via the runner, to form a second layer of the plastic part. The solidified plastic part can then be ejected from the mold.

Abstract: Apparatus for producing thermoplastic injection-molded parts reinforced with long fibers, includes a compounder having two meshing screws rotating in a same direction for continuously generating a stream of melt of thermoplastic material reinforced with long fibers. Melt is alternatingly conducted to at least two piston and cylinder units for injection into at least one cavity of an injection mold at a suitable pressure. Each of the piston and cylinder units includes a cylinder and a differential piston movably received in the cylinder and dividing the cylinder into a feed chamber and an injection chamber, wherein the piston has a relatively greater piston surface, adjacent the injection chamber, and a relatively smaller piston surface, adjacent the feed chamber.

Abstract: An apparatus having a single screw extruder and a twin screw extruder. The extruders are designed to operate intermittently in a batch-type process. The single screw extruder contains a plurality of barrel segments with an internal cavity, an inlet and a transfer die located at an outlet. The barrel segments provide processing flexibility in that the L/D ratio of the single screw extruder can be varied to accommodate various materials, fillers and material throughputs. The twin screw extruder includes a body having an internal cavity disposed therein. The body includes an inlet at a first end, an outlet at a second end and an inlet located along the length of the twin screw extruder to accept fiber material (fibers) from a side stuffer. A transfer valve is connected to the outlet of the twin screw extruder. The transfer valve controls the flow of melt from the twin screw extruder into an injection plunger.

Abstract: A method of injection molding an over-molded article in which a cavity extension associated with a core is first moved to a disengaged position and the core is inserted into a first cavity having a defined volume in a first geometrical configuration. A first injection operation is performed into the first cavity to form a first layer of the article. The core is then removed from the first cavity with the first layer of the article on the core. The cavity extension is moved to an engagement position and the core and first layer are inserted into a second cavity. The second cavity and the cavity extension engage to form a composite cavity having a larger volume than the defined volume and define a second geometrical configuration. A second injection operation is performed into the composite cavity to over-mold the first layer to form the article. The core and cavity extension are separated from the second cavity to remove the article therefrom.

Abstract: A device for molding a container is disclosed. The device will include a first member including an opening defined therein. A manifold member, operatively attached to the first member for channeling a plastic fluid to an insert means, is included. The insert means are positioned within the opening located within the first member, with the insert containing a first slide and a second slide. The first slide and second slide will have an extended position and a contracted position, and wherein the contracted position defines a cavity profile. The second member will have a first end that contains a plurality of core pins. A piston is adapted to the second end of the second member for reciprocating the second member into engagement with the insert so that the first slide and second slide are moved to the contracted position. During the reciprocating motion, the plurality of core pins are received in the cavity profile. The apparatus will further comprise heater means for suppling a heat to the fluidized plastic.

Abstract: A one-piece dispensing structure is molded by a process combining a co-injection molding first phase with a bi-injection molding second phase. In the first phase, a skin material and core material are co-injected into a mold cavity first region to form most of the major portion of the closure body. Subsequently, a movable shut-off member is retracted to expose an intermediate region which (1) is adjacent the closure structure hinge area and which (2) establishes communication between the mold cavity first region and another part of the mold cavity defining the closure lid portion. The skin material is injected through a second gate directly into the cavity intermediate region to fill the cavity intermediate region and the closure lid portion of the mold cavity. The skin material in the cavity intermediate region bonds to the previously injected skin material in the cavity first region adjacent the closure hinge.

Abstract: In a method of producing injection-molded parts, an injection mold has two mold halves and a melt feeding device for application of melt across the mold surface of a mold half, when the injection mold is open. The melt is pressed into all areas of the mold cavity, when closing the mold halves. In order to simplify the arrangement of the hot runners in the mold half, when different injection-molded parts are produced, it is proposed to apply the melt onto the mold surface by a hot runner plate which is positioned above the mold surface, whereby the hot runner plate has several melt nozzles in the form of needle seal nozzles which are operated and controlled depending on the profile required for the respective mold half.

Abstract: In producing an injection molded product by making a molten material flow from a cylinder through a plurality of gates in a die into a cavity and thereby filling the cavity with the molten material, a part of the flows of the molten material coming from a part of the gates is decreased or stopped before the flows of the molten material coming from a plurality of gate attain confluence in the cavity, and the flows of the molten material are made confluent by the flowing action of the flow(s) of the molten material coming from residual gate(s). According to the process of the present invention, the problem of mechanical properties in the injection molded products can be solved without adding any new apparatus to a general-purpose injection molding machine.

Abstract: The present invention is directed to an agitator-free mixing head and a method for agitator-free production of a reaction mixture from an isocyanate and a higher-viscous polyol formulation, wherein both constituents are fed to a mixing zone and mixed with each other therein, whereby a polyol formulation with a viscosity of at least 3000 mPa.s is fed at low pressure into the mixing zone and at least two flows of low-viscosity constituents (isocyanate and optionally low-viscous polyol) are injected into the flow of high-viscous polyol formulation at high pressure.

Abstract: A process for producing a cushioning article, which comprises: providing an injection molding apparatus having plural injection orifices, said orifices each having a discharge angle from 5° to 45° inclining from the vertical direction; injecting a thermoplastic polymer material in the form of strand from said plural orifices into a mold; and cooling said mold followed by demolding. The discharge angles of said orifices as projected into a horizontal plane each preferably has a phase difference of from 5° to 120° relative to those of adjacent orifices. Also disclosed is a cushioning article molded by the production process.

Abstract: Hard to fill large-surface-area parts and/or thinwalled configurations of optical lenses and reflective optical elements are among the difficult-to-mold thermoplastic products which require precision replication of the molding surfaces, in micro detail. We combine multiple opposing gates (to reduce the meltflow pathlength) with non-isothermal steps of firstly, heating these mold surfaces (with circulating heat transfer fluids supplied by a hot side supply system, to a temperature setpoint sufficiently high to retard solidification), then secondly, injecting the melt through these opposing gates, then thirdly, rapidly cooling to solidification (by circulating heat transfer fluids of much lower temperature, supplied from a cold side supply system).

Abstract: The knit line strength and other packing related properties both aesthetic and functional of injection molded polymeric products is improved by equipping the mold with packing pins. The packing pins are similar in construction to mold ejector pins and may also be mold ejector pins depending on mold configuration. The packing pins are sequentially actuated during or after filling of the mold to cause flow of plastic either transverse or parallel to the direction of flow in a to and from manner. The result is a kneading action in the viscous flow and an oriented layering effect in the solidified plastic much like a scarf joint at the knit line location. The irregular shape of the layers enhances the mechanical strength at the knit line in addition to increasing the likelihood that long chain molecules will re-entangle between the two melt flows at the knit line.

Abstract: Disclosed are novel molding methods for manufacturing thin thermoplastic lenses and, in particular, minus ophthalmic lenses that have thickness of about 1 mm or less at the thinnest point thereof. The molding methods disclosed provide for lenses which lack any abrasion or polishing artifacts on the surface and also lack any negative fining marks below the nominal surface.

Abstract: A molding apparatus for use in forming a flexible substrate based package comprises a plurality of pots. Two flexible substrates are installed at two sides of the pots. A plurality of sets of chips mounted on the upper surface of the substrate wherein each set of chips is in an array arrangement. The molding apparatus further comprises a plurality of runners. Each runner independently extends from one side of the pot to one side of the substrate, and connects to a cavity of a upper part of a mold disposed on the substrate through a gate. The present invention characterized in that, the molding apparatus is provided with a first communication channel formed corresponding to one side of the substrate and a second communication channel formed corresponding to the other side of the substrate. The first and the second communication channels interconnect the cavities at two opposite sides thereof.

Abstract: A molding and tentatively retaining mold 10 of the invention has a plurality of molds which are relatively movable with respect to a fixed mold, and molds a housing 31 and rear holders 32 and 33, which are respectively independent, in a plurality of cavities formed in cooperation with the fixed mold. When rear holders 32 and 33 after molding are relatively moved with respect to a housing 31 by movable molds 12 and 15 and are tentatively retained, a runner 20 for a cavity for molding the housing 31 is kept connected to the housing 31 through a tunnel gate 20a. In addition, a portion 15a of the fourth movable mold 15 for forming the cavity in the housing 31 is kept fitted to the housing 31 as it was during molding.

Abstract: In making a toothbrush of the type having a shaft-like handle (3), a neck section (4) joining the handle and a head (5) for holding a plurality of toothbrush bristles (6), the body is made of a first plastic material through an injection molding step. In order to provide the body with two or more portions (20, 21, 22) made of a second material, e.g., elastic and/or non-slip material such as rubber-like material, or a material having a color different from that of the first material, the toothbrush body is provided with recess sections (17, 18, 19). The second material is supplied through a plurality of channels (29, 30, 31, 32) into injection nozzle means (33, 34, 35) to provide injection of the second material in a single step, multi-point injection process into the recesses on the body to form the portions (20, 21, 22), the recesses (17, 18, 19) and the portions (20, 21, 22) thus being physically isolated from each other by the first material.

Abstract: Toothbrush body having a handle, a head, and a neck section joining the neck to the handle. This body is made of at least two materials, separated from each other for strength and aesthetics.

Abstract: This invention discloses a process for producing a low-noise gear. It consists in producing this gear by the technique of co-injection of a hard matter which will form the outer toothing and the axial portion for engagement on the shaft associated therewith, and of a damping matter which will form the heart of the thermoplastics gear.

Abstract: Valve gated multi-cavity injection molding apparatus for five layer molding having actuating mechanisms for reciprocating elongated valve members between four different positions. Each actuating mechanism has a front and a rear aligned cylinders, a first piston connected to the head of one of the valve members in the front cylinder and second and third pistons in the rear cylinder. The third piston has a stem portion which extends forwardly through the second piston into the front cylinder. Hydraulic pressure from four hydraulic lines connected to each actuating mechanism reciprocates each elongated valve member between the different positions. In the first closed position, the front end of the valve member is seated in the gate. In the second position, the front end of the valve member is retracted sufficiently to allow an initial amount of PET to flow from an outer annular melt channel through the gate.

Abstract: A molding and tentatively retaining mold 10 of the invention has a plurality of molds which are relatively movable with respect to a fixed mold, and molds a housing 31 and rear holders 32 and 33, which are respectively independent, in a plurality of cavities formed in cooperation with the fixed mold. When the rear holders 32 and 33 are relatively moved with respect to the housing 31 by a pair of rear-holder tentatively retaining cylinders 19 after molding, and are tentatively retained, the amount of movement of a pair of third movable molds 14 is set to be greater by a predetermined amount than an amount of movement necessary for tentatively retaining the rear holders 32 and 33, and the third movable molds 14 after movement are stopped at the moved positions until a predetermined time elapses.

Abstract: Multi-cavity injection molding apparatus for three layer molding having elongated pins for fixed pin gating or valve gating. Each elongated pin has a central melt bore extending rearwardly from its front end to a number of laterally extending bores. A low viscosity barrier material such as EVOH or nylon flows through these bores to the gate leading to the cavity. This allows coinjection with fixed pins and sprue gating in one embodiment and by valve gating in another embodiment.

Abstract: Stress-relieved molded acrylic opthalmic lenses, and injection-coining mold processes for molding stress-relieved plus and minus to high-minus diopter ophthalmic lenses of optically superior acrylic resin, able to pass standardized impact drop tests for use in eyeglass lenses, are described. The injection-coining processes use two-plate and three-plate mold assemblies. The cavity of a two plate runnerless mold is partially filled under partial tonnage, and the movable half of the mold controlled to coin and densify the acrylic resin under secondary or full tonnage, when a velocity-pressure changeover point is reached. In a process which employs a three-plate mold assembly, the lens mold cavities are partially filled under less than total clamp tonnage, with a cavity plate held by hydraulic pressure against movable half of the mold.

Abstract: A single piece tip seal for use in scroll compressors is produced using a polyetheretherkeytone base material injected into a mold having two ingates to the mold cavity.

Abstract: A method for manufacturing an integrated earplug, including the steps of injecting in a multimaterial-injection moulding machine an elongate core or body part of a thermoplastic elastomeric material which has a relatively high hardness, and an outer sealing part essentially enclosing the core or body part, at least partially, and made of a thermoplastic elastomeric material which has a relatively lower hardness. The material of the outer sealing part is softer than the material of the core or body part and has a Shore A Durometer hardness of less than about 10.

Abstract: In a method for manufacturing an air passage switching door with a seal member extending along an outer peripheral portion of a door body, when a melted elastic material for forming the seal member is injected into a mold space from plural injection gates, a flow length of the melted elastic material is set to be equal or smaller than 40 mm. Accordingly, even when the method is used for forming the air passage switching door where a length of one side seal member extending along the outer peripheral portion at one side of a rotation shaft is equal to or larger than 100 mm and a thickness of the seal member is equal to or smaller than 2.0 mm, a deformation of the seal member due to an inner shrinking force can be sufficiently restricted.

Abstract: A dispensing cap which fits on a container containing a fluid product. The cap includes a body provided with a dispensing orifice and a hinged lid which is hinged to the body about an axis. The body and lid are made of a rigid or semi-rigid material. The lid includes a plugging pip for plugging the dispensing orifice when the lid is closed. A coating of elastomeric material is arranged on the outer wall of the pip to produce a seal between the pip and the orifice when the lid is closed.

Abstract: An article having complex geometrical shape is obtained by consecutively coinjection molding a first and a second material substantially without stopping time between the two injections. Pressure, temperature and mass flow rate are controlled to obtain a homogeneous distribution of the several flows of injected material and to have them meet in a fluid condition and melt together at the meeting point.

Abstract: A method and system of operating a two stage injection molding machine wherein movement of the injection plunger in the shooting pot is coordinated with movement of the plasticizing screw and melt flow into the shooting pot such that the plunger provides minimal resistance to the melt flow into the shooting pot while avoiding the production of voids or air inside the melt. The undesired shear forces to which the melt is exposed are thus reduced, correspondingly reducing the melt degradation products which would otherwise result.

Abstract: A method of attaching an applique to a garment includes the providing of die press member and a backing plate press member. Die cavities are formed on one face of the injection molding die press member, each preferably of a uniform thickness of about 1.0-3.5 mm. The die cavities are open for communicating with a garment surface. The open area corresponds in size and shape with final design elements to be affixed to the garment. The garment is placed in-between the die and a backing plate member. The injection molding die member places its open cavity portion against the garment. The backing plate press member and die press member squeeze the garment therebetween to form a seal at the peripheral surface. The die member and an injection moldable silicone polymer are heated to a temperature of about 200-250 degrees Fahrenheit (200° F.-250° F.).

Abstract: Magnetic shields for plastic molded electricity meter frames are positioned to substantially block external magnetic fields from adversely affecting operation of meter components. The shield can be utilized with either electromechanical or electronic energy meters. In an electromechanical watthour meter which employs an aluminum disk driven to rotate through a magnetic field produced by a retarding magnet, the meter frame includes an integrally formed retarding magnet shield and an integrally formed bearing shield. The shields are coextensive with the frame, and extend from an inner periphery of the frame toward the retarding magnet and the bearing, respectively. The shields are formed of a magnetically permeable powder, such as a ferrite powder mixed with the plastic material from which the meter frame is molded. The shields divert externally applied fields away from the magnetically sensitive components of the meter without adversely affecting meter accuracy.

Abstract: A multi-cavity coinjection mold having a relatively large plurality of cavities for simultaneously molding a relatively large plurality of multi-layered articles including a) a plurality of cavity groups each defining a relatively small plurality of said cavities, a single balanced hot runner for supplying said relatively small plurality of cavities with contiguous different plastics materials, and a valve for sequentially supplying desired contiguous quantities of the plastics materials from plastics material sources, common to all of said groups, to the balanced hot runner; and b) a hot runner manifold system connected to the plastic material sources to supply the plastic materials to all of the valves; and related methods.

Abstract: There is provided a process for producing a multi-layer molded product having a plurality of thermoplastic resin layers. This process provides for (i) a step of supplying first and second molten thermoplastic resins each through first and second resin supplying gates which are temperature-controllable independently of each other, to between female and male molds kept in an open state with a time difference being provided between supply starts of the first and second resins, and (ii) a step of closing the female and male molds after completion of supply of the first and second resins. The process enables production of high-quality multi-layer molded products having a plurality of resin layers with good repeatability under relatively low resin supply pressure and by single mold closing. Further, high-quality multi-layer molded products can readily be produced without restrictions on materials used.

Abstract: There is provided a molding method for performing injection molding by using a multi-cavity hot-runner mold having a plurality of valve gates, wherein a proper holding pressure and the like are set for each cavity, a pressure holding step can be carried out, a plurality of products having an appearance free from such a defect as a sink mark can be obtained, the pressure in the cavity can be reduced by a gas pressure, and a necessary mold clamping force can be decreased. A valve for a first cavity is closed after the filling into the first cavity is finished, and a valve for a second cavity is concurrently opened to perform the filling into the second cavity. When injection is effected into each cavity in succession, a gas is injected into the filled resin, thereby to carry out a pressure holding step. The same pressure holding step is carried out for a third cavity and the succeeding cavities. As a result, a plurality of products having an appearance free from such a defect as a sink mark can be obtained.

Abstract: Improved method and apparatus for injection molding particularly useful with multiple hot runner valve gates to fill a single large mold cavity. A hot runner injection nozzle is provided having a gate through which melt is injected into a mold cavity, and a valve stem is movable on the injection nozzle between an open position permitting flow of melt through the gate and a closed position blocking the flow of melt through the gate. The valve stem is movable to at least one position between the open and closed positions restricting the flow of melt through the valve gate.

Abstract: An article of manufacture, such as an encapsulated dual lens sealed instrument cover, includes four components, namely, a first lens having a peripheral edge encapsulated by a polymeric/polymeric injection molded encapsulation or border and a second lens also have a peripheral edge encapsulated by a second injection molded polymeric/copolymeric encapsulation or border. A hermetic chamber is thereby formed between the two lenses. The first encapsulation is also provided with threads or similar fastening means to readily secure the instrument cover to an instrument “can” containing any variety of instruments, such as a nautical compass, amperage/voltage, fuel, etc. The first lens is inserted into a cavity of a mold and the first encapsulation is injection molded thereabout. The latter two components are then assembled with respect to the second lens and the second encapsulation is injection molded thereabout.

Abstract: An injection molded product, having an array of fastener elements integrally molded with and extending from a surface of the product, is molded in a closed cavity die. One half of the die has a mold surface with a region having an array of fastener element cavities extending therefrom for molding the fastener elements. The other half of the die has a mold surface aligned with the mold surface of the first mold part to define therebetween, in a closed condition, a mold cavity constructed to receive molten plastic for molding the product. The mold cavity includes a first portion comprising a majority of the volume of the mold cavity, and a second portion contiguous with the first portion and defined in part by the region of the first mold part surface having the array of fastener element cavities.

Abstract: A preform and container each having a crystallized neck finish and method of making the same, wherein the method involves introducing a first thermoplastic material into a first mold section to form a substantially crystallized neck portion of a preform, and introducing a second thermoplastic material into a second mold section to form a substantially amorphous body-forming portion of a preform. The first material may have a substantially higher crystallization rate than the second material, and/or the first mold section may be at a higher temperature than the second mold section. In one embodiment, an indexer carrying two core sets is movable between first and second cavity sets for sequentially molding the neck portions on the first core set in the first cavity set, and then transferring the cores and neck portions to the second cavity set for molding the body-forming portions.

Abstract: Various steps in the operation of an insulated runner injection molding system are automated by computer generated responses to various sensing steps or other steps to thereby reduce the performance requirements of the system operator. In automatic response to a manual operation incident to closure of a machine gate after an end-of sequence signal, a computer causes mold-cavity-encasing mold parts to be engaged. In automatic response to sensing such engagement of the mold-cavity-encasing mold parts, the computer causes the molding system to be adjusted to enable disengagement of insulated-runner-channel-encasing mold parts. In automatic response to sensing such adjustment of the molding system, the computer causes channel-encasing mold parts to be disengaged, whereupon a sprue is automatically removed therefrom in response to relative movement of the channel-encasing mold parts.

Abstract: A process for producing closed or open hollow parts of molded synthetic resin material in which a core (12) or mold body which extends into the mold cavity and is attached to a form element and supported on other form elements is situated between two mold half-shells. The core is supported by one or more movable stops (13-18) which can be retracted from the mold cavity. Plastic is injected into the mold via a first injection channel (22) with the core retained in position by the stops (13-18). Subsequently the retaining stops (13-18) are retracted and the mold cavity is completely filled via a second injection channel (23, 24, 25).

Abstract: The invention involves a multi-colored paintbrush handle having an axis (8), a first and a second extremity crossed by the axis (8), and an external grip surface (9) placed between said extremities, the handle including: a core (13) parallel to the axis (8), at least one colored raised part (14) emerging from the core (13) and externally defining at least one shaped section of the grip surface (9), and at least a first layer (16) of colored plastic material molded onto the core (13), the first layer (16) externally defining a main section (11) of the grip surface (9) and having a different color than that of the raised part (14).

Abstract: An apparatus and method for molding thermosetting polymers onto clothing. The apparatus includes at least one molding device, at least one polymer supply and a control system for controlling the operation of the molding devices and polymer supplies. The molding devices include die sets having an input member and a mold. The polymer supplies supply polymers for injection into the input members of the molding devices for use in molding three dimensional bodies of polymers onto substrates such as clothing.

Abstract: A method is provided for making a combination hub and catheter. A material is molded in a mold into a body having at least a first hub, and at least a first nose extending from the first hub. The first nose is then elongated into a catheter by moving first and second components of the mold away from one another.

Abstract: Various steps in the operation of an insulated runner injection molding system are automated by computer generated responses to various sensing steps or other steps to thereby reduce the performance requirements of the system operator. In automatic response to a manual operation incident to closure of a machine gate subsequent to removal of a sprue from channel-encasing mold parts, a computer causes the molding system to be adjusted to enable injection of molten plastic into an insulated runner channel to form the insulated runner and through the insulated runner into mold-cavities. In automatic response to sensing such readjustment of the molding system, the computer causes a predetermined quantity of molten plastic to be metered for injection to form the insulated runner. In automatic response to sensing such metering the computer causes the metered quantity to be injected into the channel.

Abstract: A multiple-plastic stream co-extruder, as for injection-molding cavities, in which the extruder is internally provided therewithin and therealong with a restrictor or throttle pin, rod or element that forces combined plastic material streams, formed with an interior core stream encased in outer and inner stream layers, into corresponding concentric annular flow stream layers that are ultimately split transversely in opposite directions into a cavity gated to the extruder, and with the core stream at a region of zero gradient in the transverse flow velocity profile within the extruder and cavity.

Abstract: A multi-stage method of insert molding is described including the steps of: providing a vertically movable first mold member with a cavity formed therein; providing a second mold member having a substantially flat upper molding surface; providing a third mold member having an upper end with a cavity formed therein; positioning an insert directly on the flat upper molding surface of the second mold member; positioning the first mold member with respect to the second mold member so that the cavity of the first mold member receives the insert; injecting a first flowable plastic material into the cavity in the first mold member to partially encapsulate the insert; allowing the first flowable plastic material to cool and solidify, thereby creating a first stage molding; removing the first mold member and the second stage molding from the second mold member; positioning the first mold member with respect to the third mold member so that the first stage molding registers with the cavity of the third mold member; inj

Abstract: A method and apparatus for molding plastic articles in two colors, particularly, the bodies of magnetic tape cassettes, in which a strong bonding force is provided between the two portions without having to form a recess and projection on the joining edges of the two portions. A slide core, which is moved in and out of a primary mold cavity between the mold of the two portions of the article, is provided with a tubular passage having an opening within the primary mold cavity along edge portions of the slide core. The slide core is fully inserted into the primary mold cavity to mold the first portion, then partially withdrawn to form a seconary mold cavity in which the second portion is subsequently molded. After molding the first portion, an adhesive is injected through the tubular passage along the edges of the first portion which will join corresponding edges of the second portion to thereby firmly join the two portions.