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Say good-bye to your thermos: self-heating and cooling cans have arrived.
By Kristi Cameron
The Metropolis Observed
January 2002
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The self-heating can is activated by pressing a button on the
container's bottom (cutaway diagram is inverted to display the heating
mechanism). This triggers a chemical reaction, mixing water and lime in
the heating chamber (represented in white). Three minutes later the
beverage in its surrounding chamber (represented in orange) is piping
hot.
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The beverage can hasn't had a real makeover since the advent of the stay
tab. (Remember the last summer you sliced your foot on a pull tab, probably
around 1979?) Two designs from Crown Cork & Seal (CCS)--one self-heating,
the other self-cooling--will change that. Each can has two chambers: one
for the contents and another for the heating or cooling mechanism. The steel
self-heating can (developed by CCS with a company called Thermotics) uses
a simple chemical reaction: pushing a plastic button underneath the can
mixes lime with water inside the heating chamber. Three minutes later you
have a steaming 140-degree beverage. (The precise final temperature
will be 70 degrees warmer than the starting temperature.) Nestlé
is currently marketing the can in the U.K. for Nescafé coffee.
So it follows that what heats up must also cool down, right? Not necessarily.
According to Dan Abramowicz, executive vice president of Corporate Technologies
for CCS (the largest packaging company in the world), the technology behind
the self-chilling can has been much harder to master. "This has been
the Holy Grail," he says. "The beverage industry has been looking
at this for decades." Tempra Technologies--a company that holds patents
for heating-and-cooling technology such as medical ice packs--partnered
with CCS to produce an aluminum can that cools through evaporation: turning
the base of the can exposes a water gel to a vacuum, cooling the can by
about 40 degrees in five minutes.
The benefit to the consumer is obvious--a cold drink in the middle
of a Grand Canyon hike or a hot one at the top of the Aspen slopes--but
at what cost? Though the cans are recyclable and the thermal agents are
relatively benign, there's definitely more package per beverage (a
12-ounce self-chilling can holds only 10.1 ounces of liquid, for example).
The cans are still being refined, so it remains to be seen whether
or not they're an improvement over energy-sucking vending machines.
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