IKEA Poland produces furniture boards that are automatically film-laminated. It is critical to ensure that the quality of the film-laminated furniture board edges meet precise quality requirements, so IKEA uses Cognex vision systems to perform fully automated inspection and ensure the highest product quality.
Decorating furniture by lamination
IKEA has around 12,000 items in its product range that feature furniture decorated with lamination. One well-known product is the "Billy" shelving system. Its shelving components are made from plastic-coated, veneered particle board. The edges are covered over by glued on plastic strips. The Billy shelving systems are currently available in a range of different colors and finishes. A key step in the production process is decorating the boards with lamination.
At IKEA Poland, a laminating machine is used for applying a film with glue to both sides of the boards. A cutting machine subsequently trims the excess material at the edges to the correct length. Even if just a few process parameters are not absolutely precise, defects will appear on the boards and compromise quality. The production process is very flexible in terms of colors and types of lamination that are applied. Currently, IKEA offers about ten different designs, such as birch, oak, colored black with wood texture, and slick colors such as white, black or pink. At an average output of 375 pieces per hour, approximately 3,000 boards are laminated every day at IKEA Poland.
Manual inspection is not an option
No defects whatsoever are allowed in the finished products. In theory, a skilled worker could perform a visual inspection of the board edges on the conveyor belt but in practice, this is not effective. A worker alone cannot check both sides of the board at the same time – not to mention the fact that it would be hardly possible to spot all the defects with the conveyor belt travelling at speeds of up to 52 m/min. Manual checking would also be hazardous to human inspectors, since they would have to get very close to the moving parts in order to spot defects – which could lead to injuries and accidents.
The systems integrator Automatech developed a machine for checking the laminated boards with an inspection system based on machine vision technology from Cognex. Automatech has devised a fully automated inspection facility for IKEA which allows for 100% quality inspection on shelving boards. The system consists entirely of Cognex Designer software and VisionPro software, a CIO-24 card and multiple 2-GigE high-resolution cameras. The components have been installed inside a machine enclosure with lighting and the quality of the decorative film on both sides of the boards is inspected as they pass through in rapid succession. The system has been designed specifically to detect and eliminate the following defects: excess glue, incomplete lamination, detachment of the film. Defective boards are processed by cutting off the parts which have been identified as failures. All defective parts are marked as damaged and sorted manually.
In this application, the system prevents boards with defective edges from entering the regular production process and eliminates the need for constant manual checks.
In the IKEA application, the 2-GigE Cameras (surface scan: 60 fps) and lighting modules are moved by precision servomotors because the width of the boards is variable (600 to 1300 mm) and the inspected area has to be approached and brought into focus quickly and precisely. This data is processed immediately after the images have been captured. The CIO-24 card makes it possible to implement machine vision solutions on industrial standard PCs. The 4-port GigE Frame Grabber permits a high processing speed even with four connected cameras. On the software side, Cognex Designer facilitates rapid creation of complete machine vision applications. This enables users to immediately enjoy the full capabilities of the accompanying VisionPro software – a smart tool that ignores noncritical changes in the appearance of test areas and which concentrates entirely on critical features. As such, it is the perfect machine vision tool for optimizing and processing images. Various calibration tools correct lens distortions, camera rotation and tilt. Using the Cognex system, Automatech has developed a highly efficient system for streamlining the inspection process at IKEA. It cuts waste from production and helps IKEA guarantee that its products fully satisfy quality requirements.