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Union Champagne ensures high quality with automatic package inspection
Keywords Inspection, Cognex, Systems, Machine vision, Electronic control
Champagne, the "king of wines", is meticulously prepared at every stage, from the selection of the grapes to the final corking before shipment - which may take place as long as seven years after the process begins. Union Champagne Co., near Epernay in the heart of the French Champagne region, tops off the process with six final inspections by a battery of four cameras, part of a machine vision system that takes the last look at each bottle before it leaves the winery.
The inspection system from Cognex Corp. was installed in October, 1997, following a full year of prototype testing. It sits at the end of the bottling line where it completes its six inspections of each bottle at speeds of up to 8,000 bottles per hour, ten hours per day.
The system enables Union Champagne to complete 95 per cent of its inspections electronically, as opposed to its former practice of 100 per cent manual inspection. That, plus the recorded data from each bottle, has given the company a much more firm hold of its Quality Assurance function.
Confirming a high standard
In a typical machine vision application, a video camera captures an image of the item to be inspected, in this case, the filled bottle. The machine vision computer then processes that image, comparing it with stored data that determines whether the bottle it "sees" is as full as the ideal it is compared with. The results of the system's analysis can then be sent to other equipment on the line, to remove defective products from the line, for instance.
The process of making sparkling champagne itself is not simple. It includes blending several different wines for flavour, followed by two fermentation stages. After this, the wine is bottled and placed in a cool cellar where aging takes place. For this part of the process, the bottle is capped with a crown cork (the crimped cap commonly used on beer bottles).
In a nutshell
Goal - High-speed on-line final inspection of champagne bottles.
How - Use machine vision to check six characteristics.
Result - Automatic inspection of 8,000 bottles per hour ensures product quality.
As the aging process nears its end, the bottles are gradually moved to an upside-down position so that any sediment fails to the cork. Then - in a step called "degorgement" - the neck of the bottle is frozen, the temporary cap removed, and the block of frozen sediment explodes out of the bottle and is discarded. The bottle of aged champagne is then sealed with the cork champagne drinkers worldwide are familiar with, and is ready for final shipment.
Today's champagne cork itself is unusual. The upper body consists of a mixture of wood parts and glue, but the lower end, which will contact the wine, is made up of two or three slices of solid "pure" wood.
To ensure product quality, final inspection is conducted by the Cognex 5600 vision system. Four cameras make the six final inspections.
The first camera checks the fill of the bottle (additional wine and sugar have been added to replace the sediment removed during degorgement). It also inspects the "set" of the cork, verifying the distance from the bottom of the cork to the top of the neck of the bottle, to make sure the cork has been completely inserted. It then verifies that the bottom of the cork is flat (to be sure that it has not split, allowing the wine to contact the glue in the upper section of the cork).
The second camera checks the "turbidity" of the wine - the amount of sediment still present in the bottle. The best champagne should be crystal clear, and cloudiness indicates the presence of sediment or poorly washed bottles.
The third camera inspects for splinters of glass in the wine. Occasionally, if a bottle explodes on the line, it may spray glass into those bottles not yet corked.
Lastly, the fourth camera inspects for opaque floating matter - like cork pieces.
Bottles found to be defective are pushed from the main production line for further evaluation. As it inspects, the 5600 system also records production data for each bottle - including anomalies found - for ongoing Quality Assurance records and reviews.
For further information contact: Colin Graves, Cognex UK, Chancery House, 199 Silbury Boulevard, Milton Keynes MK9 1JL, UK. Tel: +44 (01908) 206000; Fax: +44 (01980) 392463; Email: email@example.com