Shut-Off Valves
In multi-cavity applications, a plethora of cavities are used during production, for example, a mold may have 192 mold cavities. A mold cavity, cavity insert, nozzle tip, gate seal, or other portion of the apparatus relating to a particular mold cavity may become damaged or otherwise not function properly. In such a situation with a conventional multi-cavity injection molding apparatus, an operator must shut down the entire mold while disassembling, repairing, and reassembling the damaged or malfunctioning area. Stopping an entire production for a problem relating to one mold cavity is inefficient.
Shut-off valves are disposed within an edge-gated nozzle of an injection molding apparatus and associated with outwardly extending melt passages for delivering melt to mold cavities through respective mold gates. The shut-off valves are each independently switchable between an open position and a closed position to allow or block flow of molding material through the respective outwardly extending melt passage.
Recent US Patents
10/19/2010
7,815,431
Actuating device for shut-off needles in injection molding devices comprising needle shut-off nozzles
Gunther of Gunther Heisskanaltechnik,Germanydeveloped a drive system for shutoff needles in injection molds fitted with needle shutoff nozzles To reduce maintenance moving components are made at least in part of a self-lubricating or a diamantine material or are coated at least in part with a self-lubricating or diamantine material. (RDC 1/18/2011)
9/28/2010
7,803,306
Individual cavity shut-off valve for an injection molding apparatus
Babin et al of Mold-Masters, Canada has developed shut-off valves in the second nozzle distribution from the manifold to the various connected cavities so that each melt flow to each cavity can be controlled indepently of the other cavities. (RDC 12/8/2010)