Continual improvements gave birth to a feature we take for granted today
Published on Sep 29, 2012
By Tom Vanderbilt
Is design ever done? A 2007 study that looked at the ergonomics of can-tab pulling, for example, suggested that a larger tab would reduce discomfort. And there's always another basement tinkerer on the horizon.
NEW YORK - As a child of the 1970s, I have a distinct and curious memory about the landscapes I inhabited: They glittered with glinting metal, not the gold of El Dorado but the effluvia of the consumer society. I am talking about aluminium can tabs.
If, as the saying goes, we are never more than three (or five, or 10) feet from a spider, so too did those little trinkets - a sturdy ring pull attached to a curled, wedge-shaped "tear strip", the disposable remnant of the mechanism then used to open cans of beer or soda - rarely seem out of range: Studding the dirt dugouts of Little League, clustered near the concrete parking stops at convenience stores, sunk between seat cushions in cars, draped as a necklace around your friend's stoner older sister.
"I blew out my flip flop," noted singer Jimmy Buffett, in the song that begat a lifestyle, "and stepped on a pop top."
He was not alone: In 1976, The New York Times, commenting on beach injuries at Rockaway, noted that "a large percentage were due to cuts inflicted by discarded pop tabs".
There was an inherent problem in multipart portable consumer packaging: What to do with the sealing mechanism, once so vital and now so worthless (and dangerous), after you had opened the can? Often, it seemed, the answer was to simply chuck it.
Another solution was to deposit the pulled tab in the can. While this may have been less environmentally injurious, it was not without its dangers.
As an article in The Journal of the American Medical Association noted, at least seven children over a period of a little over three years had "been treated for complications of ingestion or aspiration of pull tabs from aluminium beverage cans".
One particularly pernicious problem is that aluminium often does not show up on X-rays; hence the appearance, in journals like Paediatric Emergency Care, of such startling articles as: Swallowed Coke Can Tab: Is It Still Stuck In The Oesophagus?
Indeed, it was at a radiology conference in 1974 that physician Lee Rogers - who had inadvertently swallowed a can tab during a basketball game - broached the idea of the can tab hazard to the medical community. And it was this single panel at a medical conference that launched a revolution in the design of our aluminium cans.
As described in the American Journal of Roentgenology, Dr Rogers' presentation triggered a media crusade, with more than 400 newspapers picking up the story.
"Aluminium pull-tabs are now common elements of our environment and inevitable offenders as foreign bodies in the oesophagus," the Journal of Paediatrics sternly noted in 1978, sounding like a Red Scare-era FBI dossier.
Can tabs were an ecological disgrace and a threat to children: Is there a more potent nexus for citizen outrage? The hunt for a new and better design was on.
But the irony is that the pull-tab, unveiled just more than a decade before, had been hailed as a remarkable solution to an age-old problem.
As its inventor, an Ohio toolmaker named Ermal Fraze, put it, "I personally did not invent the easy-open can end. People have been working on that since 1800. What I did was develop a method of attaching a tab on the can top."
Elegant engineering
PRIOR to Mr Fraze's invention, cans, both steel and aluminium, required a separate opener, the so-called "church key".
As engineering professor Henry Petroski notes in The Evolution Of Useful Things, Mr Fraze was at a family picnic in 1956, where he found "plenty of beer but no church key", and resorted to opening a brew via a car bumper. After an insomniac night and a spell at his workbench, Mr Fraze had his concept.
As Prof Petroski describes, the actual engineering - getting a top that was easy enough to pull off but could withstand the force of the can's pressure - was tricky: "Some early pull tabs were being blown off prematurely... so Fraze and other inventors came up with schemes to direct benignly the first whoosh of escaping gas away from the tab itself."
But a decade later, the solution had become a problem, and the search for a better can closure began.
The solution came from Mr Daniel F. Cudzik, an engineer with Reynolds Metals, who for years had been toiling away on what would what become known as the "Sta-Tab".
As Mr Cudzik told Studio 360, his search for a "convenience top" that was "more practical and less prone to litter" came to fruition one night when he was in living room, "half watching a movie".
While the idea might seem simple to a consumer raised on nothing but stay-on tabs, the design required some elegant engineering (and some subsequent legal battles over alleged patent infringements).
As Mr Cudzik described the problem in his 1975 patent application: "The opening construction of the invention requires a tab which must be stiff against transverse bending and yet flexible enough and tough enough at the connection between the tab end wall to permit lifting and retracting the tab without causing a fatigue crack at the connection."
The design operates both as a "second-class" and as a "first-class" lever at different points in the can-opening process - redirecting loads and shifting the fulcrum - using the inherent pressure from the carbonated beverage in its favour.
When the Sta-Tab launched in 1975, on Falls City beer and, quickly, other beverages, there was an initial period of consumer testing and education (as soberly described by The New York Times in 1976: "New Yorkers are now faced with a new problem: how to open the new Stay-On-Tabs on Coca-Cola cans currently being sold in New York"). But the Sta-Tab was here to stay.
From a waste point of view, the consequences were clear: Notes Prof Petroski, this time in Invention by Design: In the 16 years after Mr Cudzik's patent, "the stay-on-tabs alone amounted to over 4 million tons of aluminium that was recovered and recycled rather than discarded".
Curiously, the problem of ingested tabs has not gone away: a 2010 article in Paediatric Radiology identified 19 cases of accidental ingestion at a single children's hospital (with the majority radiographically invisible). Also still with us: can tab arts and crafts.
Mr Cudzik said on Studio 360 that he thought can tab design had reached a point "where I don't believe there'll be too many changes any more".
But is design ever done? A 2007 study that looked at the ergonomics of can-tab pulling, for example, suggested that a larger tab would reduce discomfort. And there's always another basement tinkerer on the horizon.
A Canadian golf course groundskeeper, for instance, is making the rounds with a new "smart tab", which tackles the ergonomics problem with a tab that curves slightly upwards. The tab also spins around to act as a kind of cover for the opening (to keep out debris and bees).
Will it catch on? Who knows - but the work of design, as much as it is about eliminating obvious flaws, is also about bringing to light the things we only realise are problems the very moment we no longer have to live with them.
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The writer is author of Traffic: Why We Drive The Way We Do, now available in paperback. He is contributing editor to Artforum, Print, and I.D., contributing writer to Design Observer and has written for many publications.