Down
Facts and Performance Sleeping Bags
FEATHERY FACTS
The down in your sleeping bag isn't just the feathers
of any old dead bird. The feathers come from the smaller clusters
found on the under plumage of waterfowl like geese and ducks. Land
fowl like chickens aren't used as the quality is too poor - although
saying that, I expect you might find quite a few chicken feathers
in your budget market stall 'puffer' jacket.
This natural fibre, while highly variable in nature, provides more
warmth per ounce than any other material. Down's unique structure
is responsible for its tremendous ability to trap warm air, with
its filaments divided and sub-divided to reach out into its surroundings,
creating dead air space that slows the movement of warm air.
By its very nature, a down-filled sleeping bag is as much as 35%
lighter than its synthetic counterpart and is infinitely more compressible,
providing the most warmth with the least bulk. Down is also known
to have the greatest longevity and it will outlast any other insulation
by three to five times, making it the most economical choice after
its initial investment. Down also helps the sleeping bag drape luxuriously
over the body and ensures good coverage and warm contact. The bigger
the down cluster the better the insulation and loft. The size of
the cluster is determined by several factors.
The bigger the bird the bigger the down cluster, so that's why
big geese make better down than smaller ducks. The climate in which
the bird is raised also has an effect, with thicker clusters being
found on birds that need more insulation (unfortunately Siberian
geese are rare). Perhaps it's for this reason that Vietnamese and
Caribbean down isn't as highly prized as more northerly grown down.
Most down is a by-product of the food industry and so the size of
a down cluster is determined by when the bird gets the chop.
China is the chief source of down and in the last 20 years they
have gone from just supplying the raw product to also manufacturing
the majority of the world's down products. This has led to a dramatic
drop in price forcing the home grown down manufacturers to move
their focus - like many western industries - from bread and butter
bags to the more specialized end of the market. Most of the 500-fill
to 600-fill down comes from Chinese geese, with the birds being
killed at only 12 weeks (weighing 2.7kg to 3.6kg).
Europe is the second biggest source of down, with its birds generally
being raised to an older age than Chinese birds, meaning most high
quality, high-fill down comes from Europe. The Euro birds get the
chop at 16 to 20 weeks (6.4kg to 7.3kg), producing higher grade
down of between 650-fill and 700-fill. The highest quality down
comes from very old birds of over two years old (9kg). Some of these
birds are 'guard geese', used to protect the other farmyard animals
and are highly prized, meaning this down is not cheap. Much of this
down is exported from the former Eastern Bloc, meaning down quality
has improved since the fall of the Iron Curtain. Perhaps this is
one of the reasons why the Poles climbed all those 8,000m peaks
in winter? (Well that, and being absolutely nails.)
Not all birds need to die to keep you warm though. Some Hungarian
geese are plucked while still alive, while the platinum premier
down comes from the living eider duck. This cliff-dwelling bird
is a protected species and so the down must be collected by hand
from its empty nests. Personally I'm not sure who I'd rather not
be - a Hungarian goose or an eiderdown collector?
One problem associated with down coming from the food industry
is the increasing early age that the birds are processed at, making
good quality down from older birds harder to come by. This is an
increasing problem with all the natural materials used by the outdoor
industry (including leather), as intensive farming lowers the life
span of the merchandise. Once you've got the raw material the next
step is preparing it so that it can be used to make your sleeping
bag.
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Facts and Performance Sleeping Bags
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