Individual cavity flow control methods and systems for co-injection molding
AssigneeMilacron LLC
InventorsJohn DUFFY, Scott HICKEY
Life of this patent
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Abstract
Methods and systems for co-extruding multiple polymeric material flow streams into a mold having a plurality of cavities to produce a plurality of multi-layer polymeric articles each having a consistent coverage of an interior core layer are disclosed herein. In an example method, a flow rate of a first skin material into a cavity is individually controlled for each cavity before initiation of co-injection of a second core material into the cavity, which may address inconsistent interior core layer coverage for articles from different cavities.
Claims22
1-6. (canceled)
A system for co-injection of multilayer plastic articles, the system comprising:
- a mold defining a plurality of cavities, each cavity corresponding to a resulting plastic article;
- a plurality of nozzle assemblies, each of the plurality of nozzle assemblies corresponding to one of the plurality of cavities, each nozzle assembly configured to inject a first material into a corresponding cavity of the plurality of cavities and configured to co-inject a second material into the corresponding cavity to form an interior layer of the second material between an inner layer of the first material and an outer layer of the first material in each cavity, each nozzle assembly including a flow initiation device for enabling and disabling flow of the first material into the corresponding cavity and for enabling and disabling flow of the second material into the corresponding cavity;
- and
- a processor programmed to
- control a first flow initiation device of a first nozzle assembly to initiate flow of the first material into a first cavity of the plurality of cavities at a first time,
- control a second flow initiation device of a second nozzle assembly to initiate flow of the first material into a second cavity of the plurality of cavities at a second time,
- control the first flow initiation device to initiate flow of the second material into the first cavity after a first specified time delay relative to the first time, and
- control the second flow initiation device to initiate the flow of the second material into the second cavity after a second specified time delay relative to the second time.
A system for co-injection of multilayer plastic articles, the system comprising:
- a mold defining a plurality of cavities, each cavity corresponding to a resulting plastic article;
- a plurality of nozzle assemblies, each of the plurality of nozzle assemblies corresponding to one of the plurality of cavities, each nozzle assembly configured to inject a first material into a corresponding cavity of the plurality of cavities and configured to co-inject a second material into the corresponding cavity to form an interior layer of the second material between an inner layer of the first material and an outer layer of the first material in the corresponding cavity;
- and
- a co-injection controller configured to execute instructions for:
- initiating flow of the first material from a first nozzle assembly of the plurality of nozzle assemblies into a first cavity of the plurality of cavities at a first time;
- initiating flow of the first material from a second nozzle assembly of the plurality of nozzle assemblies into a second cavity of the plurality of cavities at a second time;
- co-injecting the second material into the first cavity of the plurality of cavities after a first specified time delay relative to the first time;
- and
- co-injecting the second material into the second cavity of the plurality of cavities after a second specified time delay relative to the second time, wherein the second specified time delay is different than the first specified time delay.
15-20. (canceled)
Dependencies are inferred from the claim text.