Abstract: The present invention is an injection molding apparatus having a cast manifold. The manifold is made from a cast block and includes at least one pipe and a junction component fixed therein. The junction component has an axial bore having a first end and a second end, and at least one radial bore fluidly connected to the axial bore and having an opening to an outer surface of the junction component. A melt is introduced into the manifold and travels through the radial and axial bores of the junction component and through at least one pipe connected thereto to an injection molding nozzle for injection into a mold cavity. A manifold of the present invention may have a plurality of pipes and junction components to form a branched multi-level cast manifold.

Abstract: The present invention is an injection molding apparatus having a cast manifold. The manifold is made from a cast block and includes at least one pipe and a junction component fixed therein. The junction component has an axial bore having a first end and a second end, and at least one radial bore fluidly connected to the axial bore and having an opening to an outer surface of the junction component. A melt is introduced into the manifold and travels through the radial and axial bores of the junction component and through at least one pipe connected thereto to an injection molding nozzle for injection into a mold cavity. A manifold of the present invention may have a plurality of pipes and junction components to form a branched multi-level cast manifold.

Abstract: An injection molding machine for the manufacture of injection molded items, especially toothbrush bodies or toothbrushes, wherein the injection molding machine includes a mold-containing injection die (1) and an injection unit (2), especially with a screw-piston extruder or a similar material transport system. Distribution or transport channels lead from the injection unit (2) forming a distribution channel arrangement (4) to the individual mold cavities (5). One or more feeds (10) are located on the distribution channels and/or the mold cavities for at least one additive, for instance, a liquid color.

Abstract: A method of making a heated injection molding nozzle with an integral tip insert. First, an inner portion, an outer collar portion, and an electrical heating element are made and integrally brazed together in a vacuum furnace using a first nickel alloy brazing material. Then a tip insert is made having a desired configuration and seated in the front end of the inner portion and a second nickel alloy brazing material is applied around it. The second brazing material has a melting temperature which is substantially below that of the first brazing material. The tip insert is then integrally brazed in place by heating them to a temperature above the melting temperature of the second brazing material and below the melting temperature of the first brazing material. In addition to not affecting the metallurgical bonding between the other components, this allows the tip insert to be easily removed for replacement by again heating the nozzle to this same temperature.

Abstract: Injection molding apparatus having a cavity insert (10) with integral inner and outer portions (136, 138) having a cooling fluid flow channel (166) extending therebetween. In a preferred embodiment, the cooling fluid flow channel (166) is formed by a groove (164) machined in the outer surface (162) of the inner portion (136). This brings the cooling fluid flow closer to the cavity (66) and improves cooling efficiency and reduces cycle time.

Abstract: An injection molding heater (38) having one or more melt bores (78) extending therethrough to be removably mounted between the melt distribution manifold (26) and each nozzle (10) in a multi-gate injection molding system. The heater (38) has a plate-like body (92) made of a thermally conductive material and heat is provided to it by a heating element (98) which can be electrical or a heat pipe or by a heated fluid flowing through a passage (126) in the plate-like body (92). Each one or more of the heaters (38) can be connected to separately controlled power sources to separately adjust the heat provided by the heaters (38).

Abstract: Injection molding apparatus having a cavity insert (10) with integral inner and outer portions (136, 138) having a cooling fluid flow channel (166) extending therebetween. In a preferred embodiment, the cooling fluid flow channel (166) is formed by a groove (164) machined in the outer surface (162) of the inner portion (136). This brings the cooling fluid flow closer to the cavity (66) and improves cooling efficiency and reduces cycle time.

Abstract: Sprue gated injection molding apparatus for molding preforms or other products having two layers of a barrier material such as EVOH or nylon alternating between three layers of another thermal plastic material such as PET. The PET is injected by one injection cylinder into first and third melt passages which branch in a front melt distribution manifold to extend to a number of heated nozzles. The first melt passage extends through a central melt channel in each heated nozzle and the third melt passage extends through an outer annular melt channel surrounding the central melt passage to an aligned gate leading to a cavity. The barrier material is injected by another injection cylinder into a second melt passage which branches in a rear melt distribution manifold to extend to an inner annular melt channel extending between the central melt passage and the outer annular melt channel in each heated nozzle.

Abstract: Injection molding apparatus wherein a heated nozzle extends into an opening in a cooled mold. The nozzle has a locating and sealing ring made of a deformable material. After installation the locating and sealing ring contacts an inwardly tapered surface of the mold or an insert seated in the mold extending around the opening. When the nozzle is heated to the operating temperature, thermal expansion drives the locating and sealing ring forwardly into greater contact against the inwardly tapered surface. In one embodiment, the locating and sealing ring is near the front of the nozzle, and the nozzle also has a rear locating flange. During insertion of the nozzle into place in the opening and thermal expansion of the nozzle, the rear locating flange first comes into contact with an inwardly tapered shoulder extending around the opening which prealigns the nozzle.

Abstract: Injection molding apparatus having a removable nozzle seal (110) which screws onto the outside of the front end (76) of a heated nozzle (12). A mounting sleeve (98) having a threaded outer surface (104) is integrally mounted around the front end (76) of the nozzle (12). The nozzle seal (110) has a retaining portion (118) with a threaded inner surface (120) to screw onto the mounting sleeve (98) extending rearwardly from a central nut portion (112). A sealing and alignment flange portion (122) extends forwardly from the central nut portion (112) and fits into a cylindrical portion (124) of a well (14) in the mold (18) to accurately align the front end (76) of the nozzle (12) and prevent melt leakage between the heated nozzle (12) and the surrounding cooled mold (18). In another embodiment, a sealing and alignment portion (136) of the nozzle seal (110) extending forwardly into an opening (148) in the mold (18) forms the gate (90).

Abstract: Multi-layer injection molding apparatus having integral multi-layer melt dividing bushings seated in the melt distribution manifold for dividing a first melt passage extending to annular melt channels in heated nozzles. Matching melt channels machined in the front face of the first layer and the rear face of the second layer of each melt dividing bushing form a melt conduit which branches from an inlet to two spaced holes extending through the second layer. A pair of matching melt channels machined in the front face of the second layer and the rear face of the third layer of each melt dividing bushing form two melt conduits, each of which branch from one of the holes through the second layer to two of four spaced holes through the third layer. The four holes through the third layer align with four melt bores leading to the annular melt channel in one of the heated nozzles. A second melt passage may extend through a central bore in each melt dividing bushing to a central melt channel in the heated nozzle.

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: 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: Injection molding apparatus and method wherein a number of cylindrical inserts or plugs each having a curved melt duct therethrough are accurately aligned and securely mounted in spaced cylindrical openings through a melt distribution manifold. An alignment and retaining pin made of a very strong material extends from a bore in the manifold into a bore in the insert. The manifold is heated and the inserts and pins are cooled prior to insertion into place to provide very tight fits when they are at the same temperature which very accurately aligns the melt ducts through the inserts. The combination of the inserts fitting tightly in the openings and the strength of the pins is sufficient to withstand the rearward forces from the pressurized melt being injected through the curved melt ducts to retain the inserts in place.

Abstract: Injection molding apparatus having a cavity insert (10) with integral inner and outer portions (136, 138) having a cooling fluid flow channel (166) extending therebetween. In a preferred embodiment, the cooling fluid flow channel (166) is formed by a groove (164) machined in the outer surface (162) of the inner portion (136). This brings the cooling fluid flow closer to the cavity (66) and improves cooling efficiency and reduces cycle time.

Abstract: Multiple nozzle injection molding apparatus wherein each heated nozzle is screwed into a socket in a mounting base secured in place adjacent a melt distribution manifold. Each heated nozzle extends through an opening in the manifold plate and has a nut-like engageable portion extending forwardly of the cavity plate. This allows each of the heated nozzles to be easily removed for cleaning or replacement without removing the cavity plate.

Abstract: Multi-layer injection molding apparatus having integral multi-layer melt dividing bushings seated in the melt distribution manifold for dividing a first melt passage extending to annular melt channels in heated nozzles. Matching melt channels machined in the front face of the first layer and the rear face of the second layer of each melt dividing bushing form a melt conduit which branches from an inlet to two spaced holes extending through the second layer. A pair of matching melt channels machined in the front face of the second layer and the rear face of the third layer of each melt dividing bushing form two melt conduits, each of which branch from one of the holes through the second layer to two of four spaced holes through the third layer. The four holes through the third layer align with four melt bores leading to the annular melt channel in one of the heated nozzles. A second melt passage may extend through a central bore in each melt dividing bushing to a central melt channel in the heated nozzle.

Abstract: Multiple nozzle injection molding apparatus wherein each heated nozzle is screwed into a socket in a mounting base secured in place adjacent a melt distribution manifold. Each heated nozzle extends through an opening in the manifold plate and has a nut-like engageable portion extending forwardly of the cavity plate. This allows each of the heated nozzles to be easily removed for cleaning or replacement without removing the cavity plate.

Abstract: Injection molding hot runner apparatus having a cooled mold core with an elongated body portion with a front portion or head. A cooling tube extends centrally in body portion of the mold core. A cooling fluid circuit extends from the open front end of the cooling tube outwardly through a number of spaced radial bores. Each radial bore connects to an L-shaped duct leading back to a cylindrical space around the cooling tube.

Abstract: A method of making pairs of thread splits inserts used to injection mold bottle preforms. Machining a hollow outer part of the pair of thread split inserts with an opening therethrough and outer portions of two cooling conduits extending from the opening therethrough to respective inlets and outlets. Making an inner part of the pair of thread split inserts by injection molding a ceramic core with the required shape and investment casting the inner part around the ceramic core. The outer surface of the inner part having grooves to partially form inner portions of the two cooling fluid conduits. Then machining the cast inner part to fit in the opening through the outer part. Mounting the outer part around the inner part with the inner and outer portions of the two cooling fluid conduits aligned. Applying brazing material between the inner and outer parts and heating them in a vacuum furnace to integrally braze them together.