How Are Ugg Boots Are Made?
Well we all know about this Ugg Boots fashion craze that's hit
the world don't we? Those ugly fluffy looking boots that
originate from Australia. But how is the humble Ugg Boot made?
The number one essential factor needed for manufacturing a
genuine Australian Ugg Boot is the material (the sheepskin
hide).
You may be aware that their are plenty of different ugg boots
styles popping up on the internet these days. If you do a few
basic searches on the net you will find yourself a cheap pair of
non-authentic uggs somewhere, but let me tell you 99% of ugg
boots sold on the internet are made in china. China made
Australian ugg boots? Hmm how doess that work? Anyway these
China boots are maufactured using inferior sheepskin internal
material and probably suede external material which doesn't
allow the boot to breath and leaves you with a smelly boot you
wont want to put back on after 4-5 wears.
These china made copies just dont stand up to the Genuine
Australian Made Boot. So one things for sure if your interested
in buying a pair of sheepskin ugg boots on the internet or
anywhere for that matters, dont try to save a dollor or two when
purchasing your boots?
If you want a boot that's warm in winter cool in summer then you
must insist on a boot manufactured with Genuine Australian
double faced Sheepskin preferbly Australian Merino Sheepskin.
One of the questions often asked about ugg boots is:
Do you have to really kill the poor sheep just to make a pair of
sheepskin boots?
The answer is NO. Not one sheep has to be slaughted to obtain
their hide and fleece. The sheepskins are shawn of the sheep
back and the sheep regrow their fleece just like humans do hair.
It's completely painless for the sheep. I've been told by a few
old school ugg manufaturers that the sheep actually like the
experience of feeling free and would prefer to be shawn rather
than have to carry a thick thick woolen coat around with them in
the hot Summer.
Once the sheepskin hides are taken from the sheep then the
process of preparing the hide for manufacturers and ensuring the
hides are up to export standard begins.
Woolskins are usually preserved with salt prior to being
processed by tanneries. At the tannery the skins are processed
in large vessels called paddles which vary in capacity from 3000
to 15000 litres. In contrast to hide processing, in woolskin
processing mechanical action is kept to a minimum in order to
minimise felting of the wool. Rotating blades on the paddles
move the skins slowly and gently, and processing is performed at
much higher float ratios (typically 20-35 litres of water per
skin) than are used in hide processing.
Typically it takes about 10 working days for the skins to be
tanned and finished ready to be cut into panels for ugg boots.
Step 1. Tanning/ Processing
Soaking (16 hours) - The skins are rinsed in cold water to
remove excess salt and dirt from the wool and pelt. Rehydration
(soaking) of the pelt takes place in a fresh cold water float
overnight.
Fleshing - The skins are fleshed using a fleshing machine which
removes excess fat and muscle tissue from the back of the skins.
This allows for more rapid and complete penetration of chemicals
in the later stages of processing, particularly during pickling
and tanning.
Scouring (30-45 minutes) - Surfactants are used at 38oC to
remove dirt and grease (lanolin) from the wool.
Pickling (16 hours) - Prior to tanning, the skins are pickled in
a solution containing acid and salt. The salt is added to
prevent swelling of the skins by the acid. The internal pH of
the skins is lowered to approximately 2.8-3.0, thereby preparing
the skins for penetration by the tanning agent.
Tanning (16 hours) - Tanning is generally achieved by using
chromium salts which form cross-links with the collagen,
stabilising the skin structure and preventing putrefaction. The
tanning step is conducted at about 25oC and pH 2.5-3.0 to allow
for penetration of the chrome. Once penetrated, the chrome is
fixed to the collagen by raising the pH to about 3.6 using
sodium bicarbonate, and heating to about 35-40oC. This step
raises the shrinkage temperature of the skin from about 60oC to
around 100oC.
Wool Dyeing / Fatliquoring (3-4 hours) - After tanning, the wool
may be dyed a variety of colours. Wool dyeing is performed at
about pH 4.5-6 and at 60-65oC, "Pelt reserve agents" being added
to prevent the wool dye staining the pelt. After the dye is
exhausted, the pH is lowered to about 4.0 to fix the dyes to the
wool, and fatliquor is added to the bath. Fatliquors are
emulsified oils which are used in leather manufacture to
lubricate the collagen fibres, allowing them to move freely when
the skin is dried, thereby imparting softness to the skin.
Drying (4-24 hours) - Once tanned and wool dyed, the skins are
then dried in heated forced-air dryers by "toggling" the skins
to a frame. Drying is conducted at temperatures of 50-80oC.
Drycleaning (4-24 hours) - The dried skins are "drycleaned" in
either white spirit (a high-boiling petroleum fraction) or
perchloroethylene. The drycleaning removes the natural fat and
grease present within the skins.
Pelt Dyeing / Syntanning - Once the pelt grease is removed, the
skins are returned to the paddle for pelt dyeing. This step is
performed at low temperature (less than 30oC) in order to
minimise staining of the wool by the pelt dye. After pelt
dyeing, the skins are "syntanned" using synthetic tanning agents
in order to give the pelts added fullness and firmness. The
skins are then redried.
Step 2. Finishing
Once all the tanning and processing steps have been completed,
the skins are ready for final finishing prior to being used in
ugg boot manufacture.
Staking - After "conditioning" the skins to approximately 20%
moisture content, the skins are staked in a staking machine.
This softens and stretches the skin pelt, and puts a "nap" on
the pelt surface.
Combing / Ironing / Clipping - The wool is combed in a combing
machine to remove tangles and any burrs or grass seeds present
in the wool. An iron (a hot, 150oC revolving cylinder)
straightens the wool, removing the natural wool crimp. Finally,
a cylinder clipping machine is used to clip the wool pile to the
desired length, usually about 12-15 mm.
Step 3. Manufacturing
Panels are cut from the skins using a "clicking press". Once
cut, the panels are sewn together using industrial sewing
machines, then the sole is glued to the boot. Once this is done,
the boots are ready for sale!