Injection unit for injection molding machines with continuously operating plasticizing unit
AssigneeKrauss-Maffei Kunststofftechnik GmbH
InventorRainer Zimmet
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Abstract
An injection unit for injection molding machines includes an extruder as plasticizing unit and a plunger-type injection molding device that can be coupled to the injection molding machine by an injection nozzle. The plunger-type injection molding machine has an injection plunger, wherein the area in front of the injection plunger forms an injection space which is connected to a forward end of the extruder by a melt channel, with a shutoff valve disposed in the melt channel. The extruder can be continuously operated and has one or more plasticizing screws for plastification, wherein the extruder is so configured that a backup length is able to increase backwards into the extruder, when the shutoff valve is closed.
Claims8
An injection unit for an injection molding machine, comprising:
- a plasticizing unit in the form of a continuously operated extruder having a forward end and including at least one plasticizing screw which is operated to continuously rotate;
- a plunger-type injection device including an injection nozzle for interaction with an injection mold, and an injection plunger demarcating anteriorly thereof an injection space which is connected to the forward end of the extruder by a melt channel and from which a shot amount is injected into the injection mold as the injection plunger moves forward;
- and
- a shutoff valve disposed in the melt channel,
- wherein the extruder is constructed to allow a backup of plastic melt such that a backup length is able to expand backwards into the extruder, when the shutoff valve is closed, for continuous production of plastic melt by the extruder.
Dependencies are inferred from the claim text.