Abstract: A readily replaceable pin-in-sleeve device (A, B) for gas-assisted injection molding is used with a two-part mold to form an injection molded product from a plastic material. A sleeve (10) has a threaded exterior surface that is shaped to be received in a socket (130) of a mold member (210) opening into a mold cavity. A longitudinally extending bore (20) extends through the sleeve. The bore has a first portion (22) adjacent the cavity, and a second, larger diameter portion (24), spaced from the cavity. A pin (40) extends through the sleeve and has a forward section and an enlarged base, which are received in the bore first and second portions, respectively. A tortuous path for an injection fluid is defined between the pin and the bore to inhibit transport of plastic material into the device when the injection fluid is vented from the mold cavity. A filter 60 positioned in the bore, behind the pin, filters traces of plastic material from the vented injection fluid.

Abstract: According to the present invention, a hollow molded article of high quality can be produced by conducting the following steps of: providing a small-sized molding machine comprising a mold having a pair of mold halves wherein at least one of the mold halves comprises a body and a slidable block; supplying a resin in an unsolidified state between the mold halves to fill a mold cavity having a first clearance with the resin; supplying a pressured fluid into the resin lying between the mold surfaces; moving the slidable block from a first position to a second position; opening the mold until a cavity clearance becomes a second clearance which is larger than the first clearance; and opening the mold to take out the hollow molded article.

Abstract: An improved rocker panel construction includes a substantially convex show surface, a substantially concave hidden surface opposite the show surface, and a clip house mounting structure disposed on the hidden surface. The clip house structure includes a substantially planar clip surface, and substantially planar top and bottom legs attaching the clip surface to the hidden surface. The improvement consists of providing at least one hollow channel surrounded by a reinforcing rib connecting at least one of the legs to the hidden surface. The channel and reinforcing rib may run substantially longitudinally the length of the rocker panel. The channel and reinforcing rib provide a substantial increase in the strength of the attachment of the clip house mounting structure to the hidden surface while preventing the formation of sink marks in the show surface opposite the channel.

Abstract: A molding apparatus is provided for molding an elongated shaft member. The elongated shaft member (20) comprises: a main body (21) made from synthetic resin material; a hollow portion (22) formed inside of the main body (21), which extends substantially in a direction of a center axis (O1) of the main body; first and second shaft portions (23) formed at ends of the main body (21) respectively, which are smaller in diameter than the main body (21); and through-holes (24) formed in the first and second shaft portions (23) respectively, which are substantially coaxial with the center axis (O1). The molding apparatus comprises a mold (26, 27), a medium injection device (50) for injecting a hollow-portion forming medium from a medium injection portion (32), and a resin filling device (40) for filling the cavities with molten resin through a resin injection portion (31).

Abstract: A hollow molded article having no sink marks on its surface and having an excellent appearance is produced by filling a mold cavity with a resin being in a molten state and then ejecting at least a part of the resin by sucking through a resin-ejection opening and introducing gas through a gas-introduction opening into the resin inside of which being in a negative pressure. According to this process, the use of a high-pressure gas is not required.

Abstract: A method and an apparatus are disclosed for producing plastic objects with solid regions and hollow regions. The method has the following steps: a) blocking off a part of the cavity (2) of a molding tool (1), so that little or no plastic melt can reach the blocked-off region (8); b) injecting plastic melt into the unblocked region (9) of the cavity (2) of the molding tool (1); c) releasing the blockage, so that plastic melt can reach the previously blocked-off region (8) of the cavity (2); d) injecting a pressurized gas into the melt by means of at least one fluid injection nozzle (7), so that the melt injected into the molding tool is distributed into the desired regions of the cavity (2) while forming a hollow space and is pressed against the cavity walls of the molding tool (1); e) allowing the molded part (6) to cool; f) relieving the cavity (2) of the pressure of the pressurized fluid; and g) demolding the molded part.

Abstract: The present invention relates to a method for hollow injection molding. More particularly, it concerns a method for hollow injection molding a shaft-unified type resin rotator with excellent productivity. The molded article obtained by the present invention is excellent in dimensional accuracy, strength, surface appearance and recyclability of materials.

Abstract: A mold for use in a gas-assisted injection molding system includes a gas pin assembly which can be readily removed from one mold half in an open position of a mold wherein a porous insert of the assembly can also be readily removed from the housing of the assembly for easy servicing. The housing of the assembly has an elongated aperture formed therethrough in communication with a gas passageway in the mold to permit the flow of gas therethrough. The porous insert is positioned in the aperture. The insert permits the flow of gas therethrough but prevents the passage of molten plastic therethrough. The assembly also includes a holding device preferably in the form of a set screw which has a gas hole formed completely therethrough to permit the flow of gas therethrough. The set screw is threadedly secured within the housing to hold the insert stationary within the aperture and to permit ready removal of the insert from the housing after the set screw has been removed from the housing.

Abstract: Molds useful in the production of polythermal plastic resin articles are disclosed. One of the molds disclosed contains a set of a female mold member and a male mold member having opposing mold surfaces respectively, wherein at least one of the mold members has a gas passage therein; and a gas introducing member having a tip and a gas path extending therethrough, the gas introducing member being disposed in at least one of the mold members such that the tip does not protrude from its respective mold surface, the gas path being in communication with the gas passage, wherein the gas introducing member is a molded piece having at least one of grooves in a peripheral part or penetrating holes through an interior thereof, with the grooves and holes communicating with the gas passage.

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 process for manufacturing a panel of material, intended, in particular, for forming an element of internal trim for a vehicle body, such as, for example, a door panel, including at least one layer (1), in particular of thermoplastic material, constituting a core, provided with an internal face (2) and an external face (3), therefor:The core layer (1) is moulded between two dies (8, 9), with additional thicknesses (10) being provided locally, these being suitable for constituting reinforcing ribs (4) formed from the mass of the panel.Gas is injected axially under pressure into the said additional thicknesses (10) in order to push the material of the said core layer (1) in such a way as to form tubular box girders 5.The material pushed at the time of injecting the gas is diverted.From the mass of the panel, at least one protuberance (7) is formed with the laterally diverted material.

Abstract: A mirror assembly includes a mirror bracket formed integrally on the interior surface of the mirror shell utilizing gas assist to eliminate sink marks on the outer surface of the shell. The mirror bracket preferably comprises a wall extending from the interior surface of the mirror shell. The wall includes a base portion of increased thickness. A channel is formed by gas assist in the base portion, thereby creating a pair of spaced walls in the base portion of the wall of the mirror bracket.

Abstract: The invention comprises a plasticating machine for the working and forcing of plastic material into a mold, the machine including an elongated barrel housing having a first or proximal end and a second or distal end, and an elongated screw shaft with a screw flight therearound, the screw shaft being rotatably supported in the elongated barrel housing, for the working of plastic between the screw shaft and the elongated housing. At least one delivery conduit is generally longitudinally arranged within the wall of the housing. The delivery conduit with the housing wall may be arranged to heat or cool the screw and any plastic being worked therethrough. In a further embodiment, it may permit delivery of a medium within the wall, from an upstream location of the housing, into the primary flow path of any plastic being driven from the machine and into a mold.

Abstract: A double-walled container is formed by gas assist injection molding. Thereafter, the container is further processed by 1) inserting a gas between the container layers, 2) injecting a colored liquid between the container layers, 3) evacuating the void space between the container layers, or 4) pressurizing the space between the container layers.

Abstract: Molding of relatively large articles such as automobile body parts by gas-assisted injection molding with sequential gating of injected thermoplastic resin into the mold cavity. Elongated ribs in the parts form gas channels and strengthening ribs for the parts. Structural parts are made by adhesively joining two such parts made by gas-assisted injection molding through a combination of hollow ribs and joining flanges at sides of the parts.

Abstract: A mold for use in a gas-assisted injection molding system having a nozzle includes a runner shut-off subsystem which prevents pressurized gas from flowing through the runner and into the nozzle. A pair of pins are preferably mounted on a plate to move therewith between extended and retracted positions of the plate. The pins are slidably fit within one mold half of the mold to move within the runner between extended gas-blocking positions to block the flow of pressurized gas through the runner and into the nozzle and retracted positions to allow the flow of molten plastic from the nozzle, through the runner, through a gate, and into an article-defining cavity in a closed position of the mold. The runner shut-off subsystem includes a hydraulic cylinder for moving the plate and the pins relative to the mold half. Each of the pins has a free end portion which extends into another mold half of the mold where it is received and retained in its extended gas-blocking position.

Abstract: A mold for use in a gas-assisted injection molding system includes a gas pin assembly which can be readily removed from one mold half in an open position of a mold wherein a porous insert of the assembly can also be readily removed from the housing of the assembly for easy servicing. The housing of the assembly has an elongated aperture formed therethrough in communication with a gas passageway in the mold to permit the flow of gas therethrough. The porous insert is positioned in the aperture. The insert permits the flow of gas therethrough but prevents the passage of molten plastic therethrough. The assembly also includes a holding device preferably in the form of a set screw which has a gas hole formed completely therethrough to permit the flow of gas therethrough. The set screw is threadedly secured within the housing to hold the insert stationary within the aperture and to permit ready removal of the insert from the housing after the set screw has been removed from the housing.

Abstract: A tearable film having excellent tear properties contains a dispersed phase and a continuous phase, with said film formed from a composition containing a styrenic polymer, an olefinic polymer, and a compatibilizer wherein the compatibilizer is selected from the group consisting of hydrogenated or modified copolymer of styrene and conjugated diene, olefinic copolymer having a cyclic olefin unit, and chlorinated polyolefin. The film composition is subjected, without stretching, to T-die molding or inflation molding to provide a tearable film. In the continuous phase of the film, said dispersed phase having an average aspect ratio of 3 or more and/or a thickness of 1 .mu.m or less is dispersed in layers. The ratio of the continuous phase to the dispersed phase is 35-98:2-65 (% by weight). In the film, the tearing maximum torque is 60 g.multidot.cm/.mu.m or less and the tearing maximum tensile force is 10 g/.mu.m or less, and the film can be torn straightly at least in one direction.

Abstract: A method of the invention can produce a fiber-reinforced thermoplastic resin foamed product having less unevenness in a thickness of a surface layer and excellent mechanical strength. In the method, a fiber-reinforced thermoplastic resin sheet is continuously shaped into a hollow member, and a foaming resin composition containing a thermoplastic resin and a foaming agent is supplied into an interior of the obtained hollow member. The foaming agent is foamed so that the hollow member is shaped into a desired form by the foaming pressure.

Abstract: A mold for use in a gas-assisted injection molding system includes an ejector pin subsystem including a split pin which partially blocks the flow of molten plastic through a secondary runner, helps to eject solid plastic from the mold, and helps to define an article-defining cavity and the secondary runner in the mold. A first spill cavity is flow coupled by the secondary runner to the article-defining cavity. The split pin together with other ejector pins are mounted on an ejector plate to move therewith between extended and retracted positions. A second spill cavity is flow coupled by a tertiary runner to the first spill cavity if needed. The split pin, as well as the other ejector pins mounted on the ejector plate, eject plastic from the article-defining cavity, the spill cavities, and the secondary and tertiary runners in the extended position of the ejector plate.

Abstract: A gas injection apparatus for use with a gas assisted injection molding system. The gas injection apparatus includes a mold part defining an elongated bore communicating upstream with a source of gas and downstream with a mold cavity, and an elongated pin positioned in the bore and coacting with the bore to define a gas flow passage therebetween for movement of gas from the gas source to the mold cavity. The bore and pin include first, second and third corresponding portions. The pin and bore define an annular axial clearance in the first portion, a close fit with an axial linear passage in the second portion and an annular axial passage in the third portion. This arrangement ensures that the pin will remain concentric with respect to the bore so as to discourage entry of resin into the annular axial passage.

Abstract: A mold for use in a gas-assisted injection molding system includes an ejector pin subsystem including a blocking pin assembly which not only blocks the flow of molten plastic through a secondary runner but also helps to eject solid plastic from the mold. The mold also includes an adjustable overflow pin assembly and a conically-shaped spill cavity flow-coupled by the secondary runner to an article-defining cavity of the mold. The blocking pin assembly together with the adjustable overflow pin assembly are mounted on an ejector plate to move therewith between extended and retracted positions of the ejector plate. The blocking pin assembly includes a blocking pin which is slidably fit within a mold half to move between an extended blocking position to block the flow of molten plastic through the secondary runner and a retracted position to allow the flow of molten plastic through the secondary runner and into the spill cavity.

Abstract: A mold for use in a plastic injection molding system includes a venting pin assembly which can not only vent an article-defining cavity in the mold but can also eject a formed plastic article in an open position of the mold. A porous insert of the assembly permits air from the article-defining cavity to flow there-through while preventing the passage of molten plastic from the article-defining cavity in a closed position of the mold. A venting pin of the assembly in the form of a hollow ejector pin has an elongated aperture formed therethrough to permit the flow of air therethrough. The porous insert is positioned in the aperture at a gas hole formed through an end surface of the ejector pin. The insert and the gas hole are sized so that the insert and the end surface help to form a "Class A" surface on the article formed in the article-defining cavity.

Abstract: A method of producing an injection molded article, such as a pallet made of a polymeric material. The pallet having an integral rim. Said rim is manufactured by means of a gas injection procedure involving a mold and means for injecting a pressurized gas into a molten polymeric material in the mold. The injection of the pressurized gas results in at least one substantially closed circumambient hollow internal channel in the rim, wherein the mold is provided with one or more mold cavity portions with an enlarged or expandable cross-section providing the outer shape of at least parts of the rim. The mold is further provided with at least one gate for injection of a molten polymeric material, and at least one gas duct for injection of the pressurized gas into the core of the molten polymeric material. Each gas duct is connected to a reservoir cavity, which reservoir cavities collectively form a part of the mold cavity portions.

Abstract: Method and apparatus are disclosed for removing biopolymer constructs from support structures used to impart a selected shape to the biopolymer. The biopolymer construct and the support structure are in intimate at an interface and adhere to each other. The support structure includes an endcap adapted for introducing a fluid to the interface for reducing adhesion between the biopolymer structure and the support structure by applying a separating force at the interface, thereby facilitating removal between the support structure and the biopolymer construct.

Abstract: A method is provided for gas-assisted injection molding for forming a hollow product. The mold cavity is prepressurized with fluid prior to injecting the molten material into the mold cavity, and the molten material is injected into the mold cavity against the pressurized fluid to establish a resultant internal counterpressure within the molten material. A pressurized assist-gas is injected into the molten material to form a gas bubble within the molten material. The injection of molten material into the cavity is then controlled in a manner to maintain the internal counterpressure at desired levels to overcome stress forces and to control formation and movement of the bubble within the melt.

Abstract: Proposed is a process for injection molding of products (1) made of thermoplastic material, whose walls (2) enclose a hollow space (3), wherein the molten plastic is injected in a predetermined amount into the cavity or molding nest (6) of a mold (5), during and/or upon which a fluid pressure medium (gas) is applied so that with the formation of the hollow space the molten plastic is distributed along and set against the walls of the cavity or molding nest. The pressure medium (gas) is fed into the cavity or molding nest (6) and into the molten plastic at first essentially only in the direction of flow of the molten plastic and in a quantity and/or at a pressure that causes a void (8) to form within the molten plastic, terminating at a distance from the end of the flow path.

Abstract: An improvement is proposed for an injection molding method for the preparation of a wafer cassette for holding single crystal silicon wafers in alignment. While such a wafer cassette has several thick-walled portions such as reinforcement ribs, each of which is provided with a positioning groove for accurate positioning of an automatic machine for loading and unloading of wafers, such thick-walled portions in the prior art cassettes are subject to thermal shrinkage or molding sink in molding so as to cause deformation of the positioning grooves disturbing reliable positioning of the automatic machine. The improvement of the invention can be accomplished by undertaking the gas-assist method in which a gas is introduced into the cavity of the metal mold so as to form hollow cavities behind the positioning grooves to thus avoid the thermal shrinkage or molding sink due to the large wall thickness.

Abstract: A method of manufacturing disposable, single-use lipstick samplers by means of a dipping process. In a preferred form, a reservoir containing molten lipstick wax material is provided, and a spindle which is disposed above the reservoir is advanceable toward and retractable away from the reservoir. A plastic cup-shaped form having an apertured tip is applied to the spindle, which is thereafter advanced so as to submerge the tip of the form into the molten liquid wax material. The spindle and coated form are then removed from the reservoir, and a vacuum is applied through the spindle to the aperture of the tip of the form, so as to draw lipstick wax material therefrom and into the interior of the spindle. The form is allowed to cool so as to solidify the wax, and thereafter is fitted with a cover, removed, and suitably packaged.

Abstract: A gas assisted injection molding system includes a gas injection pin and gas vent pin which are independently, selectively extendable into a cavity of a mold. Each of the gas injection pin and gas vent pin include a first actuator and a second actuator. Each first actuator selectively extends and retracts the pin into and out of the cavity of the mold. Each of the second actuators selectively opens and closes a valve within the pin, thereby selectively permitting and restricting the flow of gas through the pin.

Abstract: A method is described for injection-moulding a product by means of the so-called gas-injection method. A special feature of the method is that in addition to the injection of gas into the product cavity (10) via a first gas inlet (51), gas is injected into a spill cavity (20) via a second gas inlet (52). The amount of material (1) flowing from and toward the spill cavity (20) can be controlled by the location of the second gas inlet (52). Moreover, a variant of the method prevents the formation of so-called dead ends. By means of another variant of the method in accordance with the invention it is possible to prevent the occurrence of so-called flow lines.

Abstract: A molding process in which a material with an open cell, porous structure 10 is placed, aligned or supported inside a suitable enclosed holding device. Another molding material 20 is subsequently injected into the said holding device while gas and/or pressure is sequentially applied to the said holding device, causing a synergistic interaction and joining between the said materials to take place. During the processing phase, gas is evenly dispersed throughout the porous core, effectively equalizing cavity pressure and permitting an even flow pattern to exist, encapsulating or sandwiching the said porous structure, thus forming a composite material with physical properties which are substantially greater than the individual components.

Abstract: A gas injector including a tube extending into the hollow enclosure of a housing. The hollow enclosure of the housing is connected with gas pressure. The outside end of the tube being extendable into the cavity of a plastic material injection mold. That end of the tube defines a valve seat. A valve is seatable on the seat. A rod on the valve extends through the tube into the hollow enclosure of the housing. A spring in a cup shape support normally urges the rod to move the valve onto the valve seat. A solenoid plunger acting on the rod and activated by an electromagnet moves the rod against the spring to raise the valve off the valve seat.

Abstract: A method of molding a hollow body to make the body nearly uniform in thickness around an internal opening thereof. A weir is provided in a central part of an opening portion of the mold cavity near an upstream side of the opening portion with respect to the direction of flow of a resin. Molten resin is injected into the cavity, and pressurized gas is thereafter injected into the molten resin in the cavity to make the internal opening in the resin. Since the weir is provided, the resin comes into uniform contact with the inner mold surface of the die at the opening portion as the resin flows into opening portion. The resin is uniformly cooled and solidified, starting with the inner surface and working inwardly, so that the hollow body is made nearly uniform in thickness around the internal opening.

Abstract: Disclosed is a flame retardant, high precision resin mechanical part for use in office automation machines required to function with high accuracy and high precision, which is made by injection molding a thermoplastic resin composition comprising: (A) an amorphous thermoplastic resin; (B) an inorganic filler in a scale form; and (C) a specific phosphoric acid ester in which phosphoric acid ester groups are bonded through a bisphenol.

Abstract: A gas-assisted injection mold has a gas injection nozzle protruding into a mold cavity from a mold surface that defines a part of the mold cavity. The mold surface has a barrier in a spaced surrounding relationship to the gas injection nozzle to prevent the plastic melt from being lifted away from the mold surface as gas is injected into the plastic melt in the mold cavity. The barrier may take the form of a well or a boss.

Abstract: A molded resin product can be produced without shrinkage on the surface by providing a hollow part and foam cells therein. Before molten resin containing a foaming gas is introduced into a cavity between molds, the cavity is preliminarily filled with a gas with pressure high enough to prevent the foaming gas from beginning to foam or expand. While the molten resin is injected into the cavity or after its injection is over, another high-pressure gas is injected through at least one gas injection nozzles into the resin where a hollow part is desired. As the nozzle is retracted from the cavity, the high-pressure gas is removed from the cavity, allowing the foaming gas to begin to foam and expand, forming a hollow part and foam cells inside the molded product.

Abstract: A method of making a steering hand wheel insert including the steps of: (a) in a gas assisted injection molding apparatus, forming a mold cavity having a ring-shaped outer channel, an inner channel, and a plurality of spoke channels; (b) forming a stationary mold insert in the outer channel dividing the latter into a pair of symmetric outer channel segments having downstream ends connected by a plurality of choke passages around the stationary mold insert; (c) injecting a short shot of a flowable plastic melt into each of the outer channel segments through a gate diametrically opposite the stationary insert and into the inner channel through a second gate; (d) injecting inert gas under pressure into the flowable plastic melt diametrically opposite the stationary insert; (e) maintaining the gas pressure until all of the flowable plastic melt cures in the mold cavity, (f) relieving the pressure of the inert gas, and (g) opening the mold cavity and removing the molded plastic steering hand wheel insert having a

Abstract: In a process for extruding polymer melts (25) to form hollow chamber sections (21) by pressing the polymer melt through a shaping tool (24) with an internal shaping mandrel (26) and by subsequently sizing and cooling the hollow chamber section strand in a sizing and cooling unit (31) it is provided for the sizing and cooling of the hollow chamber section strand to be carried out in the sizing and cooling unit under extrusion pressure. A device for carrying out this process is characterized in that shaping tool (24) and sizing and cooling unit (31) are rigidly connected to form a closed system so that the strand extrusion pressure prevailing in the shaping tool can be propagated into the sizing and cooling unit, and that the shaping mandrel (26) protrudes out of the shaping tool (24) into the sizing and cooling unit (31).

Abstract: The invention comprises a plasticating machine for the working and forcing of plastic material into a mold, said machine including an elongated housing having a first or proximal end and a second or distal end, an elongated screw shaft with a screw flight therearound, the screw shaft being rotatably supported in the elongated housing, for the working of plastic between the screw shaft and the elongated housing with at least one delivery conduit generally longitudinally arranged through the screw shaft, from a proximal end to a distal tip end thereof. The conduit may be arranged to be movable with respect to the screw shaft to permit delivery of a medium through the screw shaft to any plastic being driven from the machine. The medium may be any single or combination of components selected from the group comprising vapor, liquid, gas, powder or solid, to control the machine or treat any plastic being driven therefrom.

Abstract: The present invention comprises a method for delivering a medium such as a gas, vapor or liquid into a melted plastic in a mold via an elongated screw shaft rotatably supported in a housing, the method including the steps of providing the screw shaft with a bore longitudinally therethrough from a proximal end to a distal tip end thereof, rotating the screw shaft in the housing to move plastic therethrough, and into the mold, introducing a gas, vapor or liquid into the bore, to permit the gas, vapor or liquid to be delivered through the bore, and into the molten plastic in the mold through the distal tip end of the screw shaft.

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: The invention includes retrofitting a plasticating machine for the working and forcing of plastic material into a moldor die, the machine including an elongated housing having a first or proximal end and a second or distal end, and elongated screw shaft with a screw flight therearound. The screw shaft is rotatably supported in the elongated housing, for the working of plastic between the screw shaft and the elongated housing with at least one delivery conduit generally longitudinally arranged through the screw shaft, from a location proximal to the distal tip end of the screw. To accomplish such delivery, the screw shaft is replaced with a corresponding screw shaft with a bore extending through the distal tip end thereof, or the existing screw shaft is machined to have such a bore extend therethrough, from location proximal to the distal end out through the distal tip end. The bore in one embodiment may extend completely through the screw shaft, from its proximalmost end to its distalmost tip end.

Abstract: A manufacturing method of a container formed integrally includes steps of preparing a mold, forming a gas shooting hole, injecting material in the mold for forming a container, shooting gas in the mold for forming an inner hollow layer, opening the mold and taking out a shaped container, and sealing a gas hole. The manufacturing method reduces time needed in forming a container in the mold, enhancing quality of containers produced, by inertia gas shot in material for a container injected in the mold.

Abstract: An apparatus for producing plastic objects with hollow spaces is disclosed. The method has the following steps: establishing a fluid connection (9) between the main cavity (2) of a mold (1) and an overflow cavity (8) and injecting a sufficient amount of plastic melt into the cavity (2) of the mold (1) along a melt flow path, which extends from a plasticizing unit (4, 5) through a plastic injection nozzle (3) into the mold (1), such that plastic melt passes from the main cavity (2) into the overflow cavity (8). The fluidic connection (9) between the main cavity (2) and the overflow cavity (8) is then broken-off prior to the introduction of a pressurized fluid, especially a pressurized gas, into the melt in the cavity (2) by at least one fluid injection nozzle (7), so that the melt situated in the cavity (2) is distributed in the cavity (2) while forming a hollow space, and is pressed against the cavity walls of the mold (1).

Abstract: A process for producing a hollow article in an assembly comprising first and second mold members movable relative to each other between a closed position in which an inner surface of the assembly defines a cavity and an open position. The cavity is shaped to define a corresponding configuration to the article. According to this process, a charge containing at least one molten thermoplastic resin is supplied at the first and/or second mold member while the mold members are not in the closed position. The first mold member is moved relative to the second mold member into the closed position so as to define the cavity, and a first clamping force F1 is applied to the first and second mold members. The charge is then compressed within the mold cavity under the first clamping force F1. Thereafter, the clamping force is reduced from the first clamping force F1 to a second clamping force F2 before the molten thermoplastic resin in the mold cavity has completely solidified.

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 gas leaves the nozzle and a passage extending between the inlet and the outlet. The outlet includes a plurality of apertures wherein at least some of the plurality of apertures have a rectangular shape arranged such that the longitudinal axis of consecutive rectangular shaped apertures are parallel to one another and 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: Disclosed is an injection molding method for producing a shaped, hollow resin article by introducing a pressurized fluid into a molten resin mass injected into a mold cavity, wherein, during the introduction of the pressurized fluid, the temperature of at least one preselected portion of a back surface of the molten resin mass is maintained at a level which is at least 5.degree. C. higher than the temperature of a front surface of the molten resin mass, causing the fluid to flow into the molten resin mass along a line substantially corresponding to a line along which the preselected portion of the back surface extends, so that a shaped, hollow resin article produced has a hollow in a position corresponding to the preselected portion of the back surface. By the method of the present invention, the flow of the pressurized fluid introduced can be surely led to an intended portion in the molten resin mass, so that the location of a hollow in the molten resin mass can be surely controlled.

Abstract: The present invention provides a new and improved process of producing vehicle grille guards by gas-assisted injection molding and the grille guards produced thereby. The process includes injecting a plastic resin into a mold cavity in an amount less than the total volume of the mold cavity. An inert gas in then injected into a center portion of the cavity and a hollow gas channel extending throughout the center portion is formed, forcing the plastic resin to flow along an outer surface of the cavity.

Abstract: A molded resin product can be produced without shrinkage on the surface by providing a hollow part and foam cells therein. Before molten resin containing a foaming gas is introduced into a cavity between molds, the cavity is preliminarily filled with a gas with pressure high enough to prevent the foaming gas from beginning to foam or expand. While the molten resin is injected into the cavity or after its injection is over, another high-pressure gas is injected through at least one gas injection nozzles into the resin where a hollow part is desired. As the nozzle is retracted from the cavity, the high-pressure gas is removed from the cavity, allowing the foaming gas to begin to foam and expand, forming a hollow part and foam cells inside the molded product.