Automation helps packaging verification
Machine vision and code readers verify packing label quality. As with many machine vision applications proper set-up and fixturing are needed in this packaging automation system integration project.
- Food packaging automation inspects package labels.
- Project included machine vision, code readers, PLC, software, fixturing.
- Automated inspection has very high rates of reliability when system are properly integrated into the application.
Automation and controls can help packaging implementations and improve product safety and quality. Don McLeod, systems engineer at Grantek Systems Integration, answered questions from Control Engineering about a recent packaging automation project and offered advice on some of the lessons learned from the project.
Q: Can you please give a brief description of the packaging-related project?
McLeod: Food packaging needed label verification to ensure packaging quality. In the application:
- Artwork is pre-printed on packaging materials
- Verification is required to ensure that correct packaging is being used for the product being produced
- This is critical for facilities where there can be potential allergens in some products but not others.
Q: What was the scope of the project and goals?
McLeod: The goal was to ensure that all packaging and labels matched the product being produced. That included:
- Inspection of tub for 2D code
- Inspection of lid for correct graphic
- Inspection of label for case for correct product 1D product code.
Q: What types of automation, controls, or instrumentation were involved?
McLeod: The project included programmable logic controller (PLC), human-machine interface, code readers, a machine vision camera, machine vision software and industrial Ethernet. The machine vision camera trigger was hardwired to the PLC but results were handled over EtherNet/IP industrial Ethernet from ODVA. Specifically:
- Compact Logix PLC from Rockwell Automation – Trigger camera, monitor results, interface with line PLCs and manage product SKU list
- PanelView Plus 7 HMI from Rockwell Automation – Operator interface to monitor system and select SKUs
- Cognex DataMan 363 Readers with built in LED light – 2D and 1D codes
- Cognex In-Sight 7802 Camera with diffuse panel light – PatMax for lid graphics
- VisionView CE Cognex software for Rockwell Automation PanelView.
Q: What were particular challenges outlined in the project?
McLeod: Challenges for this project included installing equipment in tight spaces and ensuring 360-degree coverage of the industrial tub on the conveyer.
Q: How were those issues resolved?
McLeod: Camera coverage was ensured in the following ways.
- We designed a stand that allowed for multiple Cognex DataMan cameras to be mounted looking at the side of the tub and one Cognex In-Sight camera with a light that looks down from above.
- Six Cognex DataMan cameras were mounted to look at the side of the tube forming a circular array around the tubs as they travelled along the conveyor. This ensured that the 2D code would always appear in the field of view of the cameras.
Q: Can you share some positive metrics associated with the project?
McLeod: Two significant metrics were to avoid read rates for code readers less than 0.5% and to have zero false fails for lid Cognex PatMax software. Those were achieved.
Q: What were the resulting lessons learned or advice you’d like to share, for your firm or the customer(s) involved?
McLeod: Three points of advice are:
- For inspecting 360-degree coverage six readers work far better than four.
- Ensure that samples of all packaging materials are provided when setting up a vision system.
- Ensure that the full SKU list is provided at the start of the project to ensure that PLC memory is sized to accommodate.
KEYWORDS: Packaging automation, system integration case study
Food packaging automation inspects package labels.
Project included machine vision, code readers, PLC, software, fixturing.
Automated inspection has very high rates of reliability when system are properly integrated into the application.
Does your next machine or line redesign consider next-generation automation?