How do They Make Ugg Boots?

Nobody saw it coming, but Ugg Boots have certainly taken the world by storm and become a huge fashion craze. Everybody whose anyone is wearing them! Austrailians know that Ugg means "ugly" but these woolly sensations are still everywhere. Wondering exactly how Ugg Boots are made and just what makes them so comfortable?

Genuine Ugg Boots are made from the highest quality materials, including sheepskin hide. You can buy knockoff Ugg Boots almost anywhere, but only the real deal provides the comfort and durability promised by Ugg. If they are not made in Australia then they are not authentic. Ugg Boots are just not made in China, so don't be fooled. Buying Ugg-style boots that are not genuine will leave you with boots that are far inferior in quality. Translation: uncomfortable and smelly.

Warm in the winter and cool in the summer, genuine Ugg Boots are made from Australian double-faced sheepsking, usually Australian Merino Sheepskin. The highest quality around! Saving a couple of bucks will get you some synthetic fiber that's not the same.

Some folks wonder if any animals are harmed during the making of Ugg Boots. The short answer is, the sheep is slaughtered. BUT, that sheep was going to be slaughtered for meat to feed people-it is never actually slaughtered to obtain the sheepskin. Sheep farmers obtain a secondary profit for selling the hides in addition to the meat. So, understand that the making of Ugg Boots doesn't directly harm the sheep.

Sheepskins have to be preserved properly before they can be processed into boots. Tanneries use large vessels called paddles, that hold anywhere from 3,000 to 15,000 liters of salt water and slowly swish the skins around inside. This is a gentle process that takes about 10 days to get the hides properly tanned and ready to be cut for Ugg boots.

Step 1. Tanning/ Processing

The first step in tanning or processing of sheepskin is "Soaking," which takes about 16 hours to complete. During this process, the skins are thoroughly rinsed in cold water to remove any excess salt or dirt from the wool and pelt. This soaking process is done overnight in a vat of fresh cold water.

The next step in the tanning process is called "Fleshing." This part of the process uses a fleshing machine which removes any excess fat and muscle tissue from the underside of the sheepskins. This part of the process is essential for allowing more rapid and complete penetration of chemicals in the later stages of processing, particularly during the pickling and tanning stages.

After Fleshing comes "Scouring." This 30-45 minute segment of the process uses surfactants at high temperatures (around 38 degrees Celsius) and takes care of removing dirt and lanolin (grease) from the wool.

"Pickling" of the sheepskin then takes about 16 hours. Before the sheepskin can be tanned, they have to be ) pickled. Pickling means soaking the skins in a solution of acid and salt. Adding salt prevents any potential swelling of the skins because of the acid. It's important to lower the internal pH of the skins to somewhere between 2.8-3.0, which will allow the tanning agent to properly penetrate the skin.

The 16-hour "Tanning" step involves using chromium salts which form cross-links with the collagen, thereby helping to stabilize the skin structure and preventing putrefaction or rotting. This step is performed at room temperature, around 25 degrees Celsius, and around a pH of 2.5-3.0. Once the tanning agent (the chromium) penetrates the skin, the process is stopped, and the chrome is fixed to the collagen by raisng the pH to 3.6 using sodium bicarbonate and heating the skins to between 35-40 degrees Celsius. In doing so, the shrinkage temperature of the skin is raised to anywhere between 60-100 degrees Celsius.

Next comes "Wool Dyeing" or "Fatliquoring." This takes anywhere from 3-4 hours to complete. After the skin is tanned, the wool may be dyed any of a variety of colors. Wool dyeing needs to be done at about pH 4.5-6 and at 60-65 degrees Celsius. Special "pelt reserve agents" must be added to keep the wool dye from staining the pelt. Once the dye is stable, the pH is lowered to about 4.0 to fix the dyes to the wool, and fatliquor (emulsified oil) is added to the solution. Fatliquors are part of leather manufacturing that help to lubricate the collagen fiber and allow them to move flexibly and freely once the skin is dried. This is what makes the leather feel soft.

Drying of the skins then takes 4-24 hours. Forced air dryers are used with the skins stretched across a frame. Drying occurs at 50-80 degrees Celsius.

Drycleaning must then take place over the following 4-24 hours. Either a white spirit (high boiling petroleum fraction) or perchloroehtylene is used to remove any natural fat or grease that remains in the skins.

Following final removal of the pelt grease, "Pelt Dyeing" or "Syntanning" comes next. Back in the paddle (the soaking vessel), the pelts are dyed in cooler temperature dyes (less than 30 degrees Celsius). This minimizes staining of the wool. After the pelt dyeing is completed, syntanning involves using synthetic tanning agents to make the pelts added fullness and firmness. Finally, the skins are dried once more.

Step 2. Finishing

After the lengthy tanning process is complete, the final finishing is done so the skins may be used to make Ugg Boots.

The skins must be conditioned to approximately 20% moisture content. Staking is the process by which the skins are softened and stretched, and a "nappy" surface is added to the pelt.

Final "Combing," "Ironing," and "Clipping" then takes place to remove any tangles, burrs, or grass seeds that may be remaining in the wool. The wool is straightened using an iron to remove the natural crimp. Lastly, a clipping machine creates a uniform wool pile at a desired length (usually 12-15 mm).

Step 3. Manufacturing

A "clicking press" is used to cut individual panels from the skins. After being cut to the right size, the panels are then sewn together using special industrial sewing machines. The soles are then glued to the boot upper, and, finally, the Ugg Boots are ready for you to purchase.