Enzymes+Make+Jeans+Look+Cool+(Iris+Chen)


 * __Enzymes Help Jeans Look Cool__**

In the early 1980’s, factory producers used pumice stones to give jeans the faded look that is really popular amongst young adults today. The annual sales of jeans are part of a $700 billion global industry. In the United States, twelve pairs of jeans are literally sold every second of the day. But as time went on, people realised using pumice stones was bad for the jeans and the machines but also for the environment. That’s when they introduced “biostoning” which uses enzymes instead of stones. Cellulases and other enzymes are used widely in the textile industry, each with its own special properties.

“Stone”-washed jeans is the most common way of producing the faded effect on jeans. The name basically tells the meaning; freshly dyed jeans were loaded into large washing machines and tumbled with stones. Pumice stones give the special faded/worn look on jeans; the pumice roughens the surface of the jeans like sandpaper. Then it removes some dye particles from the surfaces of the yarn to end the affect. But the usage of pumice stones has a lot of problems both environmentally and economically but the results also fluctuate. Because the roughening of the surface is hard to control, results might not be what are wanted and a significant percentage does always get ruined because of abrasion. Too little abrasion won’t give it the desired look but too much can damage the fabric especially around the hems and waistbands. But not only does the fabric get abraded, metal buttons and rivets on jeans get as well and so does the drum of the washing machine. The stones reduce the quality of the jeans, the lifespan is shorter than one of regular blue jeans, the life of the equipment is shortened, and the production costs are increased. Environmental regulations are also pressuring industries to generate less pollution.

Finally in Europe 1989 a new technique “biostoning” was introduced which relies on the action of enzymes to selectively modify the surfaces of the jean fabric. Enzymes have been used in textile industries to remove starch and waxy residue from raw materials. The enzymes used for biostoning are called “cellulases”. The gene for the cellulase enzyme was first isolated from the fungus //Trichoderma reesei// and then put into bacteria for mass production. Cellulase breaks down cellulose which is the main component of cotton and other natural plant fibres. The cellulose on the exterior of each cotton fibre is exposed and cellulases bind to the exposed cotton fibre and break some of the molecular bonds. This process can be controlled so that only the dye particles are loosened from the denim surface but the interior of the cotton fibres are still intact. The only problem with biostoning was called “back staining” which causes discolouration of the fabric because loosened dye particles redeposit onto the back surface of the fabric. But that issue can be solved by controlling the pH level of the wash load between pH 6 to 8.

Biostoning using enzymes is the most environmental and economic friendly way of producing faded jeans. It doesn’t damage the fabric hence the jeans last longer and you still get the same look. Waste, pollution, and imperfections are greatly reduced and unlike pumice, enzymes can be recycled. Productivity can increase by 30%-50% because a small dose of enzymes can replace a dozen pounds of pumice stones. Also there is no need the rinse the stones off the jeans in several processes so that gives workers more time to produce new jeans. Pumice dust can also endanger employee health or clog up drains.

Enzymes are used for a lot of things today; tenderize meat, keep your teeth clean, turn cornstarch into sugar syrup, makes leather soft, and the list could go on!* So the next time you look at your jeans, you can tell everybody how your favourite pair of faded jeans are made and how the evolution of using enzymes occurred!


 * For more information go to [|www.novozymes.com]