Process and apparatus for compounding and injection-moulding desiccant-filled polymers
AssigneeAirsec S.A.S.
InventorsBenoit Portier, Valere Logel
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Abstract
Disclosed is an injection moulding machine, comprising an extruder for continuously producing a melt of a desiccant-filled polymer; at least one injection device fluidly connected with the extruder by a first conduit to receive melt and including an injection ram movable to a forward position for injection of melt into an injection mould and a rear position for introduction of melt into the injection device; characterized in that the injection moulding machine further comprises a sensor which allows determination of the viscosity or melt flow index of the desiccant-filled polymer. Further disclosed is a method of operating such a compounder-type injection moulding machine.
Claims11
A method of operating an injection moulding machine having an extruder for continuously producing a melt of a desiccant-filled polymer and with at least one injection device fluidly connected with the extruder and including an injection ram, comprising the steps of;
- Ascertaining a viscosity or melt flow index downstream of an outlet of the extruder by a sensor which allows determination of viscosity or melt flow index;
- Comparing the viscosity or melt flow index with a given desired viscosity or melt flow index;
- Generating a control signal in response to a deviation between the ascertained viscosity or melt flow index and the desired viscosity or melt flow index;
- and
- adjusting in response to the control signal the desiccant load in the polymer to adjust the viscosity or melt flow index to a level corresponding with the desired viscosity or melt flow index value.
An injection moulding machine, comprising:
- an extruder for continuously producing a melt of a desiccant-filled polymer;
- at least one injection device fluidly connected with the extruder by a first conduit to receive melt and including an injection ram movable to a forward position for injection of melt into an injection mould and a rear position for introduction of melt into the injection device,
- mechanism for providing and mixing at least one desiccant and at least one polymer,
- mechanism to regulate or adjust the pressure of the melt to a desired value, and mechanism to regulate or adjust the temperature of the melt to a desired value,
- characterized in that the injection moulding machine further comprises a sensor which allows determination of the viscosity or melt flow index of the desiccant-filled polymer melt, the sensor being a pressure sensor, disposed in a location selected from the group consisting of inside the extruder, downstream of the extruder, and an area between the extruder and the injection device, for ascertaining a melt pressure state downstream of an outlet of the extruder and outputting a signal commensurate with the melt pressure state,
- a control unit receiving a signal from the sensor, and
- a control or drive mechanism operated by the control unit for changing the desiccant load in the polymer according to a predetermined algorithm.
Dependencies are inferred from the claim text.