Control system and method for coinjection molding multi-layer containers

Abstract

A system for coinjection molding a multi-layer container includes an injection molding apparatus, a camera, and a controller. The injection molding apparatus is configured to coinject a plurality of polymeric materials into a mold cavity to form a multi-layer container including an inner layer, an outer layer, and a barrier layer located between the inner layer and the outer layer. The camera is configured to capture an image indicating a location of the barrier layer within the multi-layer container. The controller is configured to monitor the location of the barrier layer using the image captured by the camera, compare the location of the barrier layer to a threshold location, and provide a control signal to the injection molding apparatus based on the location of the barrier layer relative to the threshold location.

What is claimed is: 
     
         1 . A system for coinjection molding a multi-layer container, the system comprising:
 an injection molding apparatus configured to coinject a plurality of polymeric materials into a mold cavity to form a multi-layer container comprising an inner layer, an outer layer, and a barrier layer located between the inner layer and the outer layer;   a camera configured to capture an image indicating a location of the barrier layer within the multi-layer container; and   a controller configured to:
 monitor the location of the barrier layer using the image captured by the camera; 
 compare the location of the barrier layer to a threshold location; and 
 provide a control signal to the injection molding apparatus based on the location of the barrier layer relative to the threshold location. 
   
     
     
         2 . The system of  claim 1 , wherein:
 the image is captured by the camera while the injection molding apparatus is coinjecting the plurality of polymeric materials; and   the controller is configured to provide the control signal to the injection molding apparatus in response to a determination that the barrier layer has reached the threshold location, the control signal causing the injection molding apparatus to stop injecting the barrier layer into the mold cavity.   
     
     
         3 . The system of  claim 1 , wherein:
 the image is captured by the camera after the injection molding apparatus has completed coinjecting the plurality of polymeric materials; and   the control signal causes the injection molding apparatus to update a timing parameter used to inject the barrier layer into the mold cavity.   
     
     
         4 . The system of  claim 3 , wherein the controller is configured to cause the injection molding apparatus to update the timing parameter to begin injecting the barrier layer sooner or increase an amount of time for which the barrier layer is injected in response to a determination that the location of the barrier layer did not reach the threshold location. 
     
     
         5 . The system of  claim 3 , wherein the controller is configured to cause the injection molding apparatus to update the timing parameter to begin injecting the barrier layer later or decrease an amount of time for which the barrier layer is injected in response to a determination that the location of the barrier layer surpassed the threshold location. 
     
     
         6 . The system of  claim 1 , wherein:
 the multi-layer container comprises a flange configured to seal with a cover for the multi-layer container; and   the threshold location is within the flange of the multi-layer container.   
     
     
         7 . The system of  claim 1 , wherein the location of the barrier layer is a location of a leading edge of the barrier layer. 
     
     
         8 . The system of  claim 1 , wherein:
 the inner layer and the outer layer comprise a first polymeric material; and   the barrier layer comprises a second polymeric material less permeable to gas than the first polymeric material.   
     
     
         9 . A method for coinjection molding a multi-layer container, the method comprising:
 operating an injection molding apparatus to coinject a plurality of polymeric materials into a mold cavity to form a multi-layer container comprising an inner layer, an outer layer, and a barrier layer located between the inner layer and the outer layer;   capturing an image indicating a location of the barrier layer within the multi-layer container using a camera;   monitoring the location of the barrier layer using the image captured by the camera;   comparing the location of the barrier layer to a threshold location; and   providing a control signal to the injection molding apparatus based on the location of the barrier layer relative to the threshold location.   
     
     
         10 . The method of  claim 9 , wherein:
 the image is captured by the camera while the injection molding apparatus is coinjecting the plurality of polymeric materials; and   the control signal is provided to the injection molding apparatus in response to a determination that the barrier layer has reached the threshold location, the control signal causing the injection molding apparatus to stop injecting the barrier layer into the mold cavity.   
     
     
         11 . The method of  claim 9 , wherein:
 the image is captured by the camera after the injection molding apparatus has completed coinjecting the plurality of polymeric materials; and   the control signal causes the injection molding apparatus to update a timing parameter used to inject the barrier layer into the mold cavity.   
     
     
         12 . The method of  claim 11 , wherein the control signal causes the injection molding apparatus to update the timing parameter to begin injecting the barrier layer sooner or increase an amount of time for which the barrier layer is injected in response to a determination that the location of the barrier layer did not reach the threshold location. 
     
     
         13 . The system of  claim 11 , wherein the control signal causes the injection molding apparatus to update the timing parameter to begin injecting the barrier layer later or decrease an amount of time for which the barrier layer is injected in response to a determination that the location of the barrier layer surpassed the threshold location. 
     
     
         14 . The method of  claim 9 , wherein:
 the multi-layer container comprises a flange configured to seal with a cover for the multi-layer container; and   the threshold location is within the flange of the multi-layer container.   
     
     
         15 . The method of  claim 9 , wherein the location of the barrier layer is a location of a leading edge of the barrier layer. 
     
     
         16 . The method of  claim 9 , wherein:
 the inner layer and the outer layer comprise a first polymeric material; and   the barrier layer comprises a second polymeric material less permeable to gas than the first polymeric material.   
     
     
         17 . A controller for coinjection molding a multi-layer container, the controller comprising a processing circuit configured to:
 operate an injection molding apparatus to coinject a plurality of polymeric materials into a mold cavity to form a multi-layer container comprising an inner layer, an outer layer, and a barrier layer located between the inner layer and the outer layer;   capture an image indicating a location of the barrier layer within the multi-layer container using a camera;   monitor the location of the barrier layer using the image captured by the camera;   compare the location of the barrier layer to a threshold location; and   provide a control signal to the injection molding apparatus based on the location of the barrier layer relative to the threshold location.   
     
     
         18 . The controller of  claim 17 , wherein:
 the image is captured by the camera while the injection molding apparatus is coinjecting the plurality of polymeric materials; and   the control signal is provided to the injection molding apparatus in response to a determination that the barrier layer has reached the threshold location, the control signal causing the injection molding apparatus to stop injecting the barrier layer into the mold cavity.   
     
     
         19 . The controller of  claim 17 , wherein:
 the image is captured by the camera after the injection molding apparatus has completed coinjecting the plurality of polymeric materials; and   the control signal causes the injection molding apparatus to update a timing parameter used to inject the barrier layer into the mold cavity.   
     
     
         20 . The controller of  claim 19 , wherein the control signal causes the injection molding apparatus to update the timing parameter to:
 begin injecting the barrier layer sooner or increase an amount of time for which the barrier layer is injected in response to a determination that the location of the barrier layer did not reach the threshold location; or   begin injecting the barrier layer later or decrease an amount of time for which the barrier layer is injected in response to a determination that the location of the barrier layer surpassed the threshold location.