초록 ▼

Apparatus for selectively controlling the flow of at least three melt material streams through the nozzle of a machine for injection molding multi-layer plastics articles. The nozzle has, for each stream, a flow passageway terminating at an exit orifice. Sleeve means having an internal axial materia

Apparatus for selectively controlling the flow of at least three melt material streams through the nozzle of a machine for injection molding multi-layer plastics articles. The nozzle has, for each stream, a flow passageway terminating at an exit orifice. Sleeve means having an internal axial material flow passageway, communicate with the central channel and with one of the flow passageways and are movable axially and/or rotationally to block and unblock at least two orifices. Each flow passageway can include material flow directing means for balancing stream flow around the passageway and its exit orifice, and a tapered portion adjacent its orifice. Preferably, the orifices are fixed. Means can pressurize melt material in a flow passageway between the flow directing means and the associate orifice so that the start of flow of the material through the orifice is substantially uniform thereabout. Co-injection nozzle means for multi-polymer injection molding and blow molding machines are provided having valve means and/or one or more of the afore-mentioned features.

대표청구항 ▼

Apparatus for selectively controlling the flow of at least three melt material streams through the nozzle of a machine for injection molding multi-layer plastic articles from the melt materials, wherein the nozzle has a central channel open at one end, comprising a flow passageway in the nozzle for

Apparatus for selectively controlling the flow of at least three melt material streams through the nozzle of a machine for injection molding multi-layer plastic articles from the melt materials, wherein the nozzle has a central channel open at one end, comprising a flow passageway in the nozzle for each material stream, each of the flow passageways terminating at an exit orifice, at least two of said orifices communicating with the nozzle central channel at locations close to the open end, sleeve means having at least one internal axial material flow passageway communicating with the nozzle central channel and adapted to communicate with one of the flow passageways in the nozzle, said sleeve means being carried in said nozzle central channel and being moveable to selected positions to block and unblock said orifices and to bring said internal axial material flow passageway into and out of communication with said one of the flow passageways and to permit simultaneous flow of at least two polymer streams through said nozzle central channel.