Abstract: A two-piece hot runner manifold with plastic flow channels formed as recesses in the two mating surfaces. One or more mating structures, such as posts and sockets, ridge and groove configurations, or the like, are provided along the mating surfaces of the two mating manifold members. A bonding material, such as bronze, can be used to hold the two pieces of the hot runner manifold together. Cross pin members are preferred for use in securing the two mating manifold members together.

Abstract: An injection mold apparatus having two halves, a core portion and a cavity portion. One or more gas injection devices, such as porous metal devices, are located in either of the two portions of the mold. Once a charge of hot melted plastic is injected into the mold cavity, gas is injected through gas injection devices forcing the hot plastic against the opposite mold half and into any recesses and grooves. Gas seals are formed by the plastic to prevent gas in the mold cavity from reaching the exterior surface of the molded part during shrinkage of the plastic. The centers of mass of the plastic at rib intersections are optimally positioned to eliminate sink marks on the external finished surfaces of the molded parts.

Abstract: A gas injection pin mechanism for introducing pressurized gas into a mold cavity or melt stream. A stationary pin member is positioned directly in a bore or opening in a mold member without a sleeve member. The pin member is an elongated body member with a first end facing a mold cavity and a first gas passageway through the pin member connected to a second passageway that is traverse to the first gas passageway. The second gas passageway has an opening on an exterior lateral surface of the pin member and gas through the second gas passageway is introduced into the cavity in annular space between the pin member and the mold opening.

Abstract: A manifold for a multiple injection unit injection molding machine that allows the machine to be used when a standard conventional mold is attached to a platen. The manifold includes a first inlet port that is in communication with one nozzle of the machine and a second inlet port that is in communication with another nozzle of the machine. Each inlet port communicates with an inlet passage and the two inlet passages join an exit passageway at a junction. The exit passageway is in communication with an exit port to transfer fluid to a mold cavity. The manifold has a valve located at the junction to control the flow of material through the exit passageway.