Setting up a seamer - Demystifying the black art

That's why now many canmakers often don't bill customers until their products have reached the seaming machine at their customer's plant. It's all part of the service.

But it focuses a canmaker's mind on ensuring that the operation of the seaming machine is up to scratch. True seaming specialists are a declining breed, so who does the customer turn to when he's got a seaming problem. More often than not it's you.

So anything that improves the reliability and predictability of the seaming process is welcome. Likewise anything that demystifies the "black art" of keeping seaming systems in check for longer periods of production.

Two key developments are making this a reality. The first looks like it will simplify and speed up the tricky job of adjusting the seaming roll clearances correctly. The second, planned maintenance of seaming machines, is already well established.

The performance of a seaming machine is notoriously difficult to predict. Research by Ofer LaOr of Israel-based Quality by Vision has shown that while the seamers in a Japanese brewery were being adjusted to the same specifications, some of them were able to close three times more cans than others. And the machines that needed adjustment more often suffered from poor efficiency.

Quality by Vision was asked to isolate the problem and found that the technique of adjusting the clearances between the chuck and rolls by using feeler gauges resulted in too much variability. Not only was it also slow, but even two experts couldn't produce similar results.

To discover this LaOr had been using a computerised optical measuring system called the Clearance Gauge. It's being used at a Japanese brewery and a leading European brewer is now evaluating it. LaOr is very excited about the potential the system offers. The objective is to find the perfect "sweet spot", the optimum point where the seams are perfect and the seamer can go on running for the longest amount of time, he says. With today's set-ups, finding the optimum position of the rolls is difficult at best, and positioning heads in that optimum position is even more intricate.

"The situation is exacerbated for companies which need to have the same seamer produce seams for more than one type of can. Changing over rolls and repositioning them can be a lengthy and expensive process without a means like the Clearance Gauge to quickly and accurately position the rolls."

The Clearance Gauge, after being fitted into position on the seaming head of the machine, measures the clearances between the chuck and rolls and displays images of the tooling.

LaOr says that anyone can use the device to complete fast and accurate adjustment, and that variability is negligible. Once the rolls are in position, he says, extensive seam testing is superfluous and the system is able to produce accurate reports that track the position of the rolls in a seamer at a particular date.

He also suggests that it is also possible to analyse the data it produces to work out the best position for the rolls, and that this may improve upon the original manufacturer's specifications. LaOr has been working with Angelus on a 121L seamer producing 202 necked drinks cans to collect data that will better support his claims.

This may help to explain why it is possible for seamers with different clearances between the chucks and rolls to produce similar-looking seams. LaOr suspects that it's related to differences in the springback of seams.