Abstract: A multi-cavity coinjection mold and method for simultaneously producing a plurality of multi-layered articles comprising: a mold structure defining a plurality of mold cavities; a first supply source for supplying metered amounts of a first molding material; a second supply source for supplying metered amounts of a second molding material; a hot runner system in communication with the first and second supply sources for conveying the metered amounts of the first and the second materials separately to a region proximate each of the cavities; the region comprising having a pin controlled passage leading to proximate cavity by way of a gate having the same cross-section as the passage, the pin scavenging material from the passage and providing cavity packing.

Abstract: A method for molding comprises: passing molding material through a nozzle, a nozzle inlet, and a sprue; diverting the flow of the molding material into a mold cavity with a spreader; and introducing the molding material to the mold cavity. The spreader can be part of the mold or of the nozzle. In one embodiment, the mold can comprise: a mold cavity; a sprue in fluid communication with the mold cavity, the sprue having a nozzle inlet and being adapted to receive fluid from an injection nozzle; and a spreader protruding from an interior surface of the mold cavity opposite the sprue.

Abstract: An injection moulding apparatus includes a manifold having a channel receiving an injection of molten polymer and delivering the molten polymer to a nozzle assembly. The nozzle includes a nozzle gate delivering the molten polymer to a mould. A valve gate drop assembly has a valve pin extending from a valve pin cylinder which passes through an eccentric bushing in the manifold. The valve pin extends into the nozzle assembly and terminates at the nozzle gate. The valve pin is aligned with the nozzle gate and is adapted for control of flow of molten polymer through the nozzle gate by movement into and away from the nozzle gate. The movement of the valve pin is controlled by the valve pin cylinder. During operation, the manifold can undergo a change in position relative to the positions of the valve pin cylinder and nozzle assembly as a result of thermal expansion and contraction of the manifold.

Abstract: Improved hot runner valve gate piston apparatus and method includes structure and steps whereby the air piston cylinder wall transmits less than all of the compressive force between the backplate and the manifold. Preferably, a backup pad is disposed in contact with the manifold and the backplate, for transmitting some of these compressive forces. Preferably, the backup pad also transmits heat from the backplate to the manifold, reducing the temperature of the cylinder wall. A flex member is preferably provided adjacent to or integral with the cylinder for absorbing some of the compressive forces between the backplate and the manifold, and in order to maintain the air seal between the piston cylinder in the air channel in the hot runner backplate.

Abstract: To produce thick lenses of plastic material, a mold is first prepared having an inner cavity corresponding in shape to the lens for molding and having a work surface corresponding to an optical surface of the lens for molding; and liquid plastic material is then injected into the cavity of the mold. According to the invention, the injection is effected at a geometric center of the work surface and in a direction substantially perpendicular to the work surface, i.e. substantially along an optical axis of the lens for molding.

Abstract: A valve gating arrangement for an injection molding system having an insulated manner and a heated torpedo across from a gate. The valve gating arrangement includes a valve member sidably received within a passage extending through the torpedo. The valve member terminates at one end with a pin reciprocally movable into and out of the gate. An actuator is connected to the valve member to effect the reciprocal movement.

Abstract: In an injection molding machine, an apparatus for controlling movement of a pin comprising a plastic melt flow channel having an output end for delivering molten plastic injected into the channel under pressure to a mold cavity, wherein the pin comprises an elongated rod having an axis and an end, the pin being slidably mounted within the channel for movement along its axis within the channel, an electrically driven motor drivably interconnected to an actuating mechanism, wherein the actuating mechanism is drivably interconnected to the end of the pin, the motor being controllably drivable to drive the pin through movement along its axis within the channel

Abstract: An injection moulding tool comprises a hot-runner manifold plate, at least one nozzle holder resting on said hot-runner manifold plate, a shut-off needle which is movably guided in said nozzle holder, and a piston arranged in a piston chamber and adapted to be actuated by a fluid, said piston being connected to the shut-off needle and moving said shut-off needle to its various positions. The hot-runner manifold plate comprises at least one distributor channel, the nozzle holder comprises at least one supply channel which is associated with the shut-off needle, and said at least one distributor channel is connected to said at least one supply channel. A structural design of this kind is to be simplified and rendered more compact. For this purpose, the piston chamber is integrated in the nozzle holder in such a way that the piston is arranged between the shut-off needle and the hot- runner manifold plate.

Abstract: A valve-type nozzle (10) is provided for use in hot runner systems through which a plastic material melt is fed under high pressure to a separable and coolable tool having at least one mold cavity (K) for injection-molded items. The nozzle is heatable and comprises at least one needle valve (20) supported by sliding guides (28, 38), the arrangement being such that the melt, which is fed trough a material pipe (14), passes around at least a lower section (22) of the needle valve (20). The nozzle (10) further comprises, in an antechamber (30) upstream of the mold cavity (K), at least one outlet (18) adapted to receive a closely fitting needle end (24). The needle valve (20) includes in its lower section (22), upstream of the needle end, a pressure-relief arrangement that is in direct flow-connection with the antechamber (30).

Abstract: A mold assembly for making a multilayer molded article comprising: a first mold; a second mold; a shut-off pin slidably received in a resin-supplying gate opened to a cavity face of the first mold; a pin-driving unit for moving the shut-off pin among an opening position, a closing position and a projecting position; a resin-supplying unit for supplying a molten thermoplastic resin from said resin-supplying gate; and a press unit for moving the molds between an open position and a closed position.

Abstract: An injection molding machine is provided that includes a manifold for distributing plastic melt flow to one or more mold cavities. The manifold has a flow channel having an output orifice surrounded by a lower outside surface, and is expandable upon heating. The injection molding machine also includes a nozzle comprising a body mounted in a receiving aperture in a stationary housing aligned with a gate to a mold cavity, the body having a central bore for delivering plastic melt flow from the channel in the manifold to the mold cavity, the body having an upper surface for engaging with the lower surface of the manifold. The body has a lip member comprising an outer leg circumferentially spaced from an inner body section of the body, the outer leg having a surface mounted against a mounting surface of a stationary housing.

Abstract: The present invention relates to an apparatus for manufacturing a substantially flat article, such as a smart card, having at least one substantially flat edge. The apparatus includes a mold for forming the substantially flat article, which mold includes an inlet gate for allowing molten plastic material to flow into a cavity space defined by the mold. The apparatus further includes a source of molten plastic material, a passageway communicating with the inlet gate and the source of molten plastic material, and a blade or pin for pushing residual plastic material in the passageway into the cavity space formed so as to form a side edge for the substantially flat article having substantially no gate vestige. A method for manufacturing the substantially flat article is also described.

Abstract: A valve stem is mounted in a nozzle body, with the valve stem moving from an open position retracted from the injection orifice permitting the flow of resin to the mold cavity, to a closed position blocking the injection orifice and preventing the flow of resin to the mold cavity, and to an advanced position within the gate nub area to assist in the ejection of a molded part and clear the gate nub area.

Abstract: A seepage system for an injection molding apparatus includes a manifold plate with a first portion and a second portion abutting the first portion, and a seepage passage positioned between the first and second portions. The second portion may have at least a portion of a melt passage, and the seepage passage may have an outlet. The seepage system also has one or more seepage channels, with each seepage channel being connected to and in communication with the seepage passage. Moreover, the seepage system includes one or more seepage bores for receiving the flow of excess material, with each seepage bore being connected to and in communication with one of the seepage channels. Gravity is used to assist the flow of excess material from the one or more seepage bores through the seepage channels and the seepage passage.

Abstract: An injection molding machine valve gate nozzle having a rack driven valve pin actuator for moving the valve pin between open and closed positions during each holding cycle of operation. The valve pin actuator is sealed from the fluid flow stream and the nozzle body has a valve pin guide which substantially separates the melt stream from the valve pin during passage through the nozzle for enhanced long-term operation. The actuator has a modular construction which lends itself to economical manufacture and efficient use in multiple drop or single drop molding machines without modification.

Abstract: In a valve gate device and an injection mold provided with the valve gate device, a movable pin moves easily in order to properly open and close the gate, thereby preventing damage to the valve gate device and the mold. A movable pin 17 is made more durable by using a harder material for the movable pin 17 than for a valve body 11, and a slight distance can be maintained between the movable pin 17 and the valve body 11 by making the thermal expansion coefficient of the movable pin 17 smaller than that of the valve body 11, so that the problem of initial improper movement of the movable pin 17 can be eliminated.

Abstract: Valve gated multi-cavity injection molding apparatus. A number of valve pins extend forwardly from a valve pin plate, each in alignment with a gate leading to a cavity in the mold. A pair of cam bars extend beside a pair of actuator bars attached to the valve pin plate. Rectangular slide blocks attached to each actuator bar fit in diagonal grooves in the adjacent cam bar, whereby longitudinal movement of the cam bars moves the valve pin plate and the valve pins forwardly and rearwardly. The cam bars are driven longitudinally by electromechanical or hydraulic actuating mechanism to simultaneously and accurately stop the valve pins in at least three different precise positions during each injection cycle.

Abstract: A pressure-activated valve for conducting pressurized gas into a mold cavity of an injection molding apparatus is preferably constructed as an easily replaceable unit. The preferred valve includes a pin having a flared head section. The head section has a planar face transverse to an axis of the pin so as to approximately conform to a neighboring contour of the mold cavity. The valve also includes a body in which a passageway intersects a second end of the body to define a port and a flaring seat communicates through a first end of the body between the passageway and the mold cavity. A restrainer which abuts against the second end of the body includes a guideway aligned with the passageway through the body as well as at least one cross-channel which admits pressurized gas to that passageway through the port. The pin extends through both the passageway and the guideway so that its head portion is positioned near the seat.

Abstract: A valve device for an injection nozzle in an injection molding machine which includes a piston defined therein with a vertical cylindrical space having a lower portion partially receiving the injection nozzle adapted to inject molten resin into the cavity of a mold, and an upper portion partially receiving a connector adapted to connect the injection nozzle to a cylinder serving to supply molten resin. The piston also has a valve pin carrying portion configured to vertically support a valve pin in such a fashion that the valve pin moves vertically. The valve pin carrying portion extends diametrically across the cylindrical space of the piston. The valve pin carrying portion of the piston is provided at a central portion thereof with a hole for carrying a head of the valve pin in such a manner that the valve pin extends downwardly in a vertical direction. In this valve device, it is possible to not only obtain an optimum stroke of the piston, but also to minimize the size of the valve device.

Abstract: A valve for controlling the flow of fluent plastic material from an injection molding machine to a mold cavity. The valve includes an axially slidable valve pin that interacts with a material outlet to control flow through the valve selectively. The valve pin is actuated by an eccentric cam arrangement that positively drives the valve pin between positions where it is engaged with or disengaged from the material outlet. The cam acts on the valve pin only in an axial direction to avoid wear occasioned by side loads imposed on a valve pin.

Abstract: A valve gating apparatus and method for injection molding includes at least one shutter disposed between the gate and the cavity melt channel into a mold cavity. The shutter is moved laterally, between a closed position wherein flow of melt from the nozzle into the cavity is inhibited, and an open position wherein flow of melt into the cavity is unimpeded by the shutter. Intermediate these two positions, the shutter can be employed to reduce the cross sectional area of the gate to throttle the gate. Embodiments are disclosed wherein one shutter or pairs of shutters are employed to gate the gate. Further, when pairs of shutters are employed, the shutters can abut each other in the close position or can overlie each other. This novel design prevents generation of waste material and eliminates the need to have devices for removing cold plugs.

Abstract: An injection nozzle with a cushion ring is disclosed. In the injection nozzle used for injecting pressurized and melted resin into the cavity of a mold during an injection molding process, an axial hole is formed at the lower end of a nozzle body with an annular step being formed at the upper end of the axial hole. A nozzle tip is axially received in the axial hole and is stepped at its external surface, thus forming a stop shoulder at the external surface. The nozzle tip is brought into contact with the core of the cavity at its lower end during an injection molding process. A cushion ring, made of a stainless steel and having an O-ring shape, is interposed between the annular step of the axial hole and the top end of the nozzle tip. The stop shoulder of the nozzle tip is stopped by a stop ring, thus retaining the nozzle tip in the axial hole of the nozzle body.

Abstract: A method for injection molding plastic material items and an appropriate mold are disclosed. The mold comprises at least one cavity and a gate channel for feeding molten plastic material to the cavity. The gate channel is connected to the cavity through an opening. The molten plastic material is injected into the gate channel and through the opening into the cavity. A piston may be displaced along the gate channel and over the opening for interrupting flow of molten plastic material into the cavity and for shearing off the molten plastic material along the opening, thereby closing the cavity.

Abstract: The present invention relates to a method and apparatus for molding a tamper-evident closure with tabs that extend radially inward and upward. In order to produce tabs with such a configuration, the present invention employs a tab forming element having a mold surface with an inclination corresponding to the degree to which the tabs are desired to extend radially inward and upward. After the tabs have been molded in their inclined position, they are withdrawn from the mold, temporarily altering their angle of inclination. After removal of the closure from the a first portion of the mold, the tabs are returned to the original angle of inclination through contact with a second portion of the mold.

Abstract: A disc is provided which includes a disc body of disc shape having a center hole. An information recording area is formed on one side surface of the disc body. The information recording area has information thereon read by reflection of laser light. The information recording area has an inner circumferential edge positioned adjacent to the center hole. The disc body has a radius ranging from 39 mm to 80 mm, the center hole has a radius ranging from 7.5 mm to 7.55 mm, and the inner circumferential edge of the information recording area being positioned to extend from a radius of 15 mm to 22 mm from the center of the disc body.

Abstract: A method is disclosed for making a multi-layer up molded article.

Abstract: A valve gated injection molding system to facilitate improved melt flow to the gate of the nozzle. The system includes an annular flow insert through which the valve pin passes. The annular flow insert includes an annular groove on its outer surface. The edge of the annular groove is spaced from the wall of the melt channel so that some of the melt can flow longitudinally between the edge of the groove and the wall, while the remainder of the melt flows in the groove. The flow direction initiated by the annular flow insert eliminates flow separation and dead spots about the valve pin. The system also includes an actuator assembly including a sled attached to the valve pin.

Abstract: A method and apparatus for the manufacture of optical polymer contact lenses in a closed mold, where a mold cavity is created between a front curve insert and a back curve insert, the side walls of the mold cavity being formed by the inner wall of a movable annular gate collar, the collar being positioned in a retracted position during polymer dosing and then moved prior to polymer cure into an extended position to complete the mold cavity and to separate the polymer curing inside the mold cavity from any waste polymer outside of the mold cavity.

Abstract: A valve gated injection molding system to facilitate improved melt flow to the gate of the nozzle. The system includes an annular flow insert through which the valve pin passes. The annular flow insert includes an annular groove on its outer surface. The edge of the annular groove is spaced from the wall of the melt channel so that some of the melt can flow longitudinally between the edge of the groove and the wall, while the remainder of the melt flows in the groove. The flow direction initiated by the annular flow insert eliminates flow separation and dead spots about the valve pin. The system also includes an actuator assembly including a sled attached to the valve pin.

Abstract: A valve gate injection nozzle includes a valve stem for guiding molten resin to a molding area. The valve stem includes an input area for receiving the molten resin, a central area following the input area for processing the molten resin and an output area following the central area for connection of the nozzle with the molding area. The central area includes a first zone for splitting the molten resin into a plurality of streams, a second zone for mixing and homogenizing the molten resin, and a third zone for combing the plurality of streams and forming recombined molten resin for subsequent direction in a homogenized state to the output area. The nozzle further includes a nozzle body portion for enclosing the valve stem, wherein the nozzle body portion preferably includes means for heating the resin. An injection molding system incorporating this nozzle as well as a method for homogenizing molten resin are also disclosed.

Abstract: A device for injection molding articles of plastics material having hollow spaces. The device includes a molding tool with a mold cavity. Plastics material melt is fed to the mold cavity through a nozzle. Another pressurized medium is supplied to the mold cavity through a hollow needle at a location different from the location of the nozzle. A needle core is mounted in the hollow needle. The needle core is axially displaceable within certain limits. The opening of the hollow needle to the mold cavity can be opened and closed or its cross-sectional area can be varied by moving the needle core.

Abstract: A valve pin actuator for a valve-gated injection molding system. The actuator has an annular piston mounted in and movable back and forth along an annular bore along a pin axis. The piston extends radially outwardly of any melt passages fluidly communicating with an injection molding nozzle. A tie bar extends substantially diametrically across the piston for securing an upper end of a valve pin extending into the injection molding nozzle to cause the valve pin to move axially with the piston thereby moving the valve pin between open and shut positions.

Abstract: A needle valve nozzle (1) with injection mold (2) has a channel (11) for injection molding of flat workpieces form its narrow side. The channel (11) lies in the interior of the valve needle (10) belonging to the nozzle and extends over a partial longitudinal region of this valve needle (10). The channel (11) has an inlet (12) in the interior of the housing (6) of the needle valve nozzle (1) and at least one lateral exit (13) at an outlet before the free end (10a) of the valve needle (10) facing the injection mold (2), so that the open position of the needle valve nozzle provided for injection molding is reached by pushing the valve needle (10) with this exit (13) so far out of the housing (6) that the lateral exit (13) comes to lie at the level of the mold or cavity to be filled, while for the closed position, the valve needle (10) with this exit (13) can be retracted into the housing (6).

Abstract: Valve gated injection molding apparatus having a valve member with a cylindrical front end portion. A one-piece insert mounted at the front end of a nozzle has both a gate and locating blades extending inwardly from an outer body into a central opening leading to the gate. The inner surfaces of the blades fit around the front end portion of the reciprocating valve pin to guide and very accurately locate it in alignment with the gate. Very accurately maintaining the front end portion of the reciprocating valve pin in alignment with the gate allows it to be cylindrical rather than tapered which produces a much cleaner gate mark.

Abstract: A die for injection molding for charging molten resin onto a surface material set on the cavity surface is disclosed. The die comprises direction changing means for changing the direction of flow of the molten resin charged through the gate to directions along the surface of the surface material. The direction changing means may be a substantially conical direction changing member for changing the direction of flow of the molten resin. Since the direction changing means can change the direction of flow of the molten resin charged into the die, which is completely closed or slightly open, to directions along the surface of the surface material, the molten resin does not strike the surface material. Thus, damage to the surface material in the neighborhood of the gate can be prevented, and the surface material can be protected against the collision with molten resin which is at a high temperature and under a high pressure.

Abstract: Mold bushings or nozzles for gas-assisted injection molding processes are disclosed. The devices include movable shut-off mechanisms which selectively facilitate or prevent the passage of molten plastic material into mold cavities. One or more apertures, such as holes, openings, channels, slits, slots, and the like, are provided at or adjacent the end of the pin members or at the end of the devices. The apertures are thin or small and have dimensions which will allow the passage of gas and at the same time prevent the plastic material from plugging or clogging them.

Abstract: A valve gate assembly including a movable valve stem for guiding molten resin to a molding area, a nozzle body portion enclosing the valve stem and a mold cavity for receiving molten plastic to form a molded part formed between cooperating first and second mold halves. An injection orifice is provided downstream of the valve stem communicating with the mold cavity for transfer of the molten plastic to the mold cavity, and a movable core pin is provided contacting the valve stem and movable between a forward position opening the injection orifice and a rearward position closing the injection orifice.

Abstract: A needle seal nozzle assembly for a plastics injection machine, injection mold or hot-runner system, includes a housing defining a passageway for feeding a melt from an inlet to an outlet, with housing being formed by a first housing portion having one end facing the inlet, and by a second housing portion facing the other end of the first housing portion and having an interior forming part of the passageway. The first housing portion includes a substantially cylindrical tubular body which defines a fluid channel that forms another part of the passageway and is fluidly connected to the interior of the second housing portion. Received in fluidtight manner between the first and second housing portions is a slide for displacement between a first position in which a fluid flow through the outlet is cut and a second position in which the flow of melt is open through the outlet.

Abstract: A valve pin (24b) of a valve for injecting molten resin is inserted into a cavity (31) formed in a mold (22), then the molten resin is injected and filled by way of a gate (30) into a space formed between the valve pin (24b) and the cavity (31). Then the molten resin is cooled and solidified so as to provide a molded product of synthetic resin.

Abstract: A gas nozzle for a gas assisted injection molding system includes a body having an inlet in fluid communication with a source of pressurized gas, an outlet through which the gas leaves the nozzle and a passage extending between the inlet and the outlet. The outlet includes a plurality of apertures arranged in a predetermined manner relative to one another such that the flow path through the outlet approximates a 1/8 inch hole but does not clog with resin over successive plastic injections into the mold.

Abstract: A needle valve nozzle (1) with a nozzle housing (3), a needle valve (10) arranged axially displaceably in it in the center, and a needle guide (4) constructed as a bushing, has its material feed channel (5) completely in the interior of this needle guide (4). The needle guide (4) has a corresponding radial dimension on the face (11) of the needle valve nozzle (1) and of the nozzle housing (3), and jointly forms the face (11). It is furthermore provided that this bushing-like needle guide (4) has an insulating spacing from nozzle housing (3), in particular on its exterior, preferably with the aid of an air gap, so that a heat outflow though the nozzle housing (3) and its abutment (16) is largely ruled out.

Abstract: A mold gate and a method of using the same, in which the mold gate has an adjustable-area and width, annular access opening to each mold cavity. As the area is adjusted, the flow of molten plastic to the cavity is controlled for the injection molding of plastic parts. The adjustment may be made by rotating an outer rotary bushing relative to an inner stationary bushing, which is surrounded by the outer rotary bushing in one embodiment, and which projects beyond it in another. The position of a hot probe is thus controlled to vary the area of the access opening. Cooling lines in the vicinity of the hot probe may be provided for significant improvement of operation. Also, a method is disclosed in which the gate operates without closure by means of metal parts. Rather, the frozen molding compound itself serves to close the gate between mold shots.

Abstract: An injection nozzle has an annular gate directing a flow of plastic melt into an annular opening in a mold cavity. A valve sleeve is shifted over the gate to control outflow of plastic melt.

Abstract: A valve gate injection nozzle includes a valve stem for guiding molten resin to a molding area. The valve stem includes an input area for receiving the molten resin, a central area following the input area for processing the molten resin and an output area following the central area for connection of the nozzle with the molding area. The central area includes a first zone for splitting the molten resin into a plurality of streams, a second zone for mixing and homogenizing the molten resin, and a third zone for combing the plurality of streams and forming recombined molten resin for subsequent direction in a homogenized state to the output area. The nozzle further includes a nozzle body portion for enclosing the valve stem, wherein the nozzle body portion preferably includes means for heating the resin. An injection molding system incorporating this nozzle as well as a method for homogenizing molten resin are also disclosed.

Abstract: Method and apparatus for adjusting either the flow area to a constant size mold gate or the area of a variable mold gate opening in order to control the flow of molten plastic to a mold cavity for the injection molding of plastic parts, such adjustment being made by rotating an outer rotary gate bushing relative to an inner stationary hot sprue bushing which is surrounded by said outer rotary gate bushing.

Abstract: A mold assembly has a fixed mold incorporating a base with a movable member supported thereon so as to be movable relative thereto and which is closed against a movable mold by a spring. A protrusion on the base passing through the movable member, and a recess on the movable mold engage to form a cavity. A runner and a gate are formed between the movable member and movable mold. Resin is filled into the cavity with the mold lightly closed and the movable member and movable mold closed, but with the movable member and base apart. During filing, the movable member and base open under resin pressure which is held constant inside the cavity. The movable member and base are then closed and when the gate closes with engagement of the protruding and recess portions, a constant amount of resin remains in the mold cavity, which is then compressed.

Abstract: A system for injection molding of large components is disclosed that provides for the production of higher quality large molded components with a reduction in both molding cycle time and molding costs. Plasticized material communicates with a mold, having at least one single cavity, through a manifold that has at least two spaced valve gates that are independently opened and closed as directed by a controller to selectively communicate plasticized material to the mold cavity at separate locations in the mold cavity. The controller directs the valve gates to sequentially open and close during the filling phase so as to achieve the desired melt front advancement within the mold cavity. Once the mold cavity has been filled as desired, the valve gates are closed to effectively seal the manifold from the mold cavity.

Abstract: A valve member locating insert to be mounted in the front end of an injection molding nozzle. The locating insert has an outer mounting collar portion and a concentric inner collar portion which receives the reciprocating valve member to accurately locate it to prevent damage around the gate. The inner collar portion is connected to the outer collar portion by a single connecting vane portion. Melt flows through the locating insert in a C-shaped space between the collar portions. The vane portion and the inner collar portion have upstream and downstream ends which extend diagonally to be washed by the melt flow to avoid deadspots and reduce turbulence.

Abstract: An injection molding valve member having a smaller neck portion leading to a short head portion. This facilitates the backflow of melt around the head portion as the valve member is driven forwardly to the closed position. In one embodiment, the neck portion is formed by a number of flutes spaced around the valve member having lands between them.

Abstract: Consequently, the resin molding can be coated over the whole surface with a coating material uniformly and with an excellent adhesion.A molding material is compressed and molded with a mold comprising split molds and capable of forming a space between them outer periphery and slidable position of which are tapered, the molds are mutually separated before complete curing to define a space between at least one side surface of the molding and an opposing surface of the mold, a gas flow is formed inside the molds and in a direction towards the outer periphery for discharging any foreign material such as molding-flash and dust through the space to the exterior of the molds, and a fluid coating material is injected in the space between the molding and the surface of the mold and, with the molds clamped again, compressed to be cured.