Printed product inspection

Printing is one of those niche areas of manufacturing that keeps itself to itself. People in printing tend to stay in printing, and as a non-printer myself, it’s not an industry I’ve had much to do with. But like most manufacturing sectors, they use machine vision, and judging by “Prinect Inspection Control for Heidelberg” (published on the Printoolz blog, August 27th, 2010,) printing press manufacturer Heidelberg incorporates one of the best systems.

For details I went to the Heidelberg website where I found this product description. It’s rather sketchy but at the same time, it sounds like an interesting vision application. A feature I particularly liked was the ability to insert tags at the beginning and end of a defect.

To explain: paper is delivered to a press in roll form, printed and then cut, folded and collated. Presses run at high speed so if a defect is seen in the web there’s not a whole lot that can be done about it. So what Heidelberg do is place a tag on the stack of printed paper to show where the flaw was first seen, and a second to show where it disappeared (assuming it did.) With a stack of printed paper marked this way, separating out the defective product is a simple task.

It seems to me this approach could be applied to just about any form of web inspection – maybe it already is, but if so it’s outside of my experience. If you have information on this to share, please do.