Abstract: A method for the prevention of drooling from a plastic injection molding mold and injection nozzles. The method comprises the steps of varying a volume of a sprue in injection molding mold by movement of a plunger in a nozzle touch member inserted into the sprue, automatically returning the plunger previously moved by the nozzle touch force to its original position as the nozzle touch force decreases when the nozzle moves away after injection molding has been carried out, and increasing the sprue volume equal to an amount of movement thereof more than when injection is made to reduce the residual pressure to the extent that no drooling is introduced while maintaining said nozzle in contact with said nozzle receiver.

Abstract: A sprue bushing for an injection molding machine comprising a body surrounding a core. The core has a central passageway for flow of the plastic from the nozzle of the machine to the mold and has on its exterior surface longitudinal grooves. Assembly of the body and core forms fluid channels with the grooves. The temperature of the bushing is controlled by the flow of water through the channels.

Abstract: An injection blow-molding machine comprising a pair of female mold-halves attached to a movable plate and a fixed plate respectively with a required number of parison cavities and blow-molding cavities being formed symmetrically in the mating plane of the mold-halves, a required number of male molds each having a blowing hole therethrough ahd supported around a male-mold supporting member fixed to a rotating shaft passed freely rotatably through one of the female mold-halves attached to the fixed plate, a hot-runner block provided adjacently to each of said parison cavities, a hot-runner nozzle disposed between the parison cavity and the hot-runner block, and a gate in the form of a channel provided for each parison cavity for forming the bottom portion of the parison to be apart from said hot-runner nozzle.

Abstract: Thermoplastic articles with highly porous cores and less porous or nonporous skins are injection-molded with the aid of a nozzle having a flow divider disposed upstream of its sprue for splitting the oncoming plastic mass into a homogeneous outer stream and an inner stream admixed with a foaming agent, the two streams merging inside the gate of a mold cavity. The foaming agent enters through a central channel which may be provided with one or more ducts alternately usable to introduce pressure fluid and coolant into the cavity lined with coalescing layers of nonfoamed and foamed plastic. The flow divider may be axially movable within the nozzle to serve as a control valve and flow regulator.