How to avoid surface defects
Inspection system for coating lines ensures more quality in production
Automated coating lines can now be supplemented with an online inspection system. Four cameras are used to simultaneously check coatings and edges of sheets or web goods for cleanliness as well as correct position and size.
The Hamburg-based engineering company Ibea has been developing visual systems for the building materials and packaging industries for over 30 years. Ibea has developed the Coating Master inspection system for inspecting coated surfaces and sheet goods. The system can be used to optimize coating lines and increase production quality. The customer- and product-oriented inspection systems include hardware and software.
To monitor the edges of the product for cleanliness, correct position and size, the Coating Master is installed directly behind the coating unit above the conveyor belt. The enclosure is explosion-proof due to the risk of explosion in some coating operations. During ongoing production, sheets or plates are continuously scanned and defective sheets are sorted out. The inspection of web or continuous material is also possible.
The user can define the defect size and contrast for two types of defects: In relation to the edges, the number, position, register marks and width can be defined. In terms of coating defects, he can define flaws in the coating, unwanted pores and contamination.
The system offers simple monitoring of all four edges (multiscan) of plates or sheets. To do this, the Coating Master is equipped with four additional matrix cameras that take the appropriate images as they pass through the system's tunnel to capture all edge areas. After all images have been captured, the inspection for all tests is then performed within 0.1 seconds. Application-specific limit values are defined in advance. The algorithms used are based on these. In comparison with the limit values for size, contrast and cluster width, these calculate whether the goods receive an IO or NIO (okay, not okay) in the inspection report. The system assumes ideal surfaces. Up to 40 variants can be easily read in during the run. Ibea has integrated the "Teach & Go" process into the majority of its inspection systems. This frees the user from on-site programming tasks. Thanks to "Teach & Go", operation is simplified and the system can be set to inspection mode in just a few seconds.
In addition to the defect type (classifier), the Coating Master provides information on the defect location and defect size. Defect images can be viewed at any time in the so-called "walk by" monitor to assess whether the system is working optimally. The user can save the defect images for documentation purposes. Another helpful feature is the "Indicator Browser". With this, the tendency of the inspection can be monitored already after a short run: Approaching defects, such as a gradually fading color image, are immediately displayed to the operator (Warning). The operator can take remedial action before rejects occur. This is also a factor in optimizing production or widening defect tolerance.
As a cycle rate, up to approximately 1,600 parts per minute can be inspected by the system at a medium resolution (4,000 pixels for the line scan camera SW and 1,000 pixels for the edge scan cameras SW). Higher resolutions result in corresponding reductions in the cycle rate. For endless inspections, the representations are made section by section. In addition, however, the indication of the running meters is faded in, so that an appropriate marking can take place. In addition, for continuous products that are rolled up, a marker flag can also be glued to the edge, which works at speeds of up to 1.8 meters per second.
It goes without saying that the system is virtually maintenance-free. In productions with high dust levels, cleaning of the glass covers may be necessary. In most cases, this is not necessary, as both cameras and illuminators are mounted with the glass surface inclined to the floor. Additional cleaning devices such as blow nozzles or foil curtains can be applied for difficult production processes.
and how the color image is changing. In this way
errors can be eliminated in good time.
can be eliminated in good time (Image: Ibea)
can be transferred at any time (Image: Ibea)
Inspecting edges and surfaces simultaneously
In addition to dimensional inspection, the system simultaneously finds possible inhomogeneous areas in the coating to prevent defectively coated or contaminated sheets from passing through the drying process.The system signals whether intervention is necessary. In addition, the user no longer needs to take random samples for edge measurement or register control, as these areas are clearly displayed via the inspection image. The Coating Master thus significantly reduces scrap and sorting costs and minimizes unplanned maintenance stops for troubleshooting. The system is fully networkable, meaning statistics and images can be transferred at any time. Thanks to the very detailed statistics and in conjunction with a server viewer, conclusions can be drawn about the reasons for less than optimal production. For example, the influence of weather conditions or supplier materials can be analyzed. The system can also be operated via Teamviewer and the Internet. This makes it easy to monitor and operate the system from anywhere in the world. Accordingly, service is also carried out from Ibea's headquarters. All surface inspection users have been able to optimize their production by up to 15% with the help of the Coating Master. As a system integrator, Ibea offers its customers consulting, training and remote maintenance.
Engineering Office for Electronics and Automation GmbH www.Ibea.de