Method for thermally monitoring process for forming plastic blow-molded containers

A method of controlling a blow molding production line based on measuring the placement of material forming a blow-molded plastic container produced on the production line, the method comprising the steps of:

• providing an extrusion blow molding machine having a plurality of molding stations each comprising a mold and a parison extruding system, wherein the extrusion blow molding machine provides an output of plastic blow-molded containers, wherein each plastic container comprises a continuous sidewall and a base;
• measuring the placement of material forming the sidewall and base of the containers by:
• detecting heat emitted from the container via infrared light with an infrared camera to form an infrared image of the container after the container is released from the mold;
• converting the detected infrared light image into corresponding electrical signals;
• transmitting to a microprocessor the electrical signals;
• comparing in the microprocessor the electrical signals with stored data regarding desired material distribution forming the plastic container;
• and
• producing output information regarding the placement of material forming the plastic container and, if the output information indicates that a bottle has a material distribution that is a deviation from the desired material distribution, manually performing at least one of the following steps:
• i. adjusting at least one parameter of the extrusion blow molding machine to bring material placement within the desired material distribution;
• and
• ii. stopping the production line.