Over The Horizon

Can-do Knowhow

Brian Langham

Next time you open a tin of baked beans for lunch, stop and think that the tin end you have removed is one of more than three-quarters of a billion such ends made each year in Hamilton. That’s a mountain of ends – and it has taken the expertise of a team of Industrial Research engineers to ensure that every single one of them is leak proof.

Steel Can Components (SCC), a New Zealand Dairy Board and Australian packaging company Amcor joint venture to make can components for the food and dairy industries, opened a factory 12 months ago on the outskirts of Hamilton.

It is a sophisticated and highly-mechanised setup that runs 24 hours a day, five days a week, cutting, shaping, lining and leak-proofing 1,330 can ends a minute – or 850 million ends each year.

The leak-proofing is one of the last steps in the chain, but a vital one – it’s what lies between the tomato sauce from your baked beans and your car’s upholstery, as your family drives home from the supermarket with the weekly shopping.

SCC production coordinator Lee Broderick says the company had looked at an overseas camera system for checking the soundness of the ends’ seals but found it was prohibitively expensive and so approached Industrial Research for help.

Industrial Research operates a machine vision business unit, Industrial Vision Solutions, that customises and integrates machine vision technology systems for industrial clients.

Industrial Vision Solutions’ Terry Palmer and James Preddey designed a four-camera inspection system for about half the price of the overseas model, and SCC is now installing the system on each of its three can-end production lines.

The software-driven cameras check to make sure there is a consistent and not too thin spread of sealing compound around the inside lip of the end, Broderick says.

A faulty end is quickly rejected by the system. As hundreds race noisily down the conveyor belt from the cameras, you can see that what looks like a perfectly good seal to the eye appears badly pockmarked on the system’s computer display unit, and a swift and dispassionate jet of air blows it off the belt into a reject bin, as the others queue up for a final 15-second oven-baking.

Palmer says the project was thought "nearly impossible" when work began but with clever use of high-intensity, strobing ring-lights to illuminate under the rim of each end, a 120^o wide-angle lens to see under the rim, and software to process the images, the camera system is now able to inspect 30 ends every second.

Palmer says only one other firm in the world makes such an inspection system and Industrial Research plans to market its system overseas.

"We’re drawing up plans for a second generation model where parts can be easily inserted and removed and which will automatically adjust itself for different sized ends, and we are looking forward to introducing it to can manufacturers here and overseas."

Brian Langham is with Industrial Research Ltd.