Latest inspection systems defeat web defects
Whether you manufacture filmstock, laminate and slit film, or print labels, you know providing your customer with defective product isn’t an option. At the very least, bubbles, scratches or holes will result in spending additional time, money and energy to make good, putting your trustworthiness and continued business under your customer’s microscope. So why not get on the other end of the proverbial microscope, seeking out and destroying web defects by using the latest defect detection systems?
KEEPING A SHARP, SMART EYEDuring its formative years, web defect detection systems were reserved for precious few converters, usually performance or pharmaceutical packaging manufacturers where the nature-and laws-of the industry required its use. Gradually, though, web inspection migrated into mainstream applications, a movement driven largely by discerning customers, surrounding competition, and generally good business sense, as Robert Chiricosta, director of marketing at Cognex, explains.
“At the end of a shift, the end of a day, or the end of the week, an inspection system ultimately ensures an increased yield of first-rate product compared to second quality stock,” says Chiricosta.
Chiricosta explains that as the use of web inspection systems gain popularity in converting operations, the capabilities and ease of use likewise increase thanks to ever-improving technology and added features. Such technology allows Cognex’s web and surface inspection system, called SmartView, to first detect and locate trouble spots on a web, then determine the nature of the defect-be it a tear or foreign material-before recording the location of the defect within the web. The system can then generate a report of defects, giving downstream operators an opportunity to proactively address, and if possible, correct, web defects.
SEEKING DEFECTS, BALANCEJack Woolley, general manager at PC Industries, notes a definite push toward faster and more complete inspection. He points out, however, than an effective web inspection system really is a balance of key variables.
“In any inspection application, the important factors are web width, defect size and speed,” says Woolley. “If I have to find missing periods in four point type, I have to have cameras and systems capable of such a fine resolution. Then I have to throughput all that data, so I have to have a computer that’s capable of handling that information.” Woolley explains that if a user reduces the defect size or increases the width of the web to be inspected, web speed is likewise reduced. For these reasons, web inspection companies like PC Industries sit down with customers to develop the exact specifications required of a web inspection system. This customization process not only helps define the ideal mixture of performance and value, but also ensures the system protects against defects whose costs go beyond company ledgers or aesthetic appeal.
“I think the primary point that [customers are] looking for is any defect in the type-missing periods are important,” says Woolley. “As an example, if a dosage is supposed to be 2.0 mg of morphine and all of a sudden that decimal point is gone, you could really harm somebody.”
REDEFINING ROLESTraditionally, wide web printers using defect detection performed their inspections on press, while narrow web converters performed their inspections near winding stations. But as Lance Shumaker, president of Advanced Vision Technology explains, these established positions are now changing.
“What’s happened in wide web more and more is customers are looking to do inspection on the slitters, laminators and rewinders because it’s the final quality control step on the way out the door,” says Shumaker. “In the narrow web world, they're putting inspection on press because that's where they see return on investment."
Shumaker explains that quality and cost reduction are key drivers here, but customer satisfaction will remain a primary driver no matter where a system is placed. “It’s still back to the primary principles-your return on investment is a happy customer that continues to buy more product,” says Shumaker. n
Advanced Vision Technology