external image image?compatible=true&tid=2&fid=0&lan_code=0&cache=1&id=TWtEPifyuaHwJeans would be boring if they all looked the same. That's why so many clothing companies strive to find new designs and new fashions for new jean styles. So, just what is it that makes so many different looks possible? Whether your denim is faded or downright worn, the answer to its origin is enzymes, particularly amylase, pectinase, catalase and cellulase.

What are enzymes?

Enzymes are substances, usually proteins, which help with chemical reactions both around and within us. They are catalysts, which means that enzymes quicken the time it it takes for a specific chemical reaction to happen, but without actually changing itself chemically. For example, there are enzymes in our digestive system which help with the breakdown of food. Without them, it would take weeks for our food to digest! external image enzymes.jpg

In order for the correct chemical reactions to occur, enzymes can only work in specific environments of certain pH levels (acidity or alkalinity) or temperature. The significance of this is that jean companies must use a particular enzyme solutions for particular jeans, since different dyes are of different pH. Also, the pH levels or temperature of a solution can be manipulated to either start or stop enzymes from reacting. Enzymes also have specific shapes, which allow only specific products to attach to the enzyme and either be broken down into smaller products ( degradation) or combined to produce a larger product ( synthesis). The picture ( click to enlarge) at right shows how substances called substrates find their specific enzyme and go through a chemical reaction to either degrade or synthesize. Most enzymes share a common prefix with the substrate that they break down: lactase breaks down lactose, maltase breaks down maltose, and cellulase breaks down cellulose. For more information on enzymes and to watch a helpful animation, visit http://www.northland.cc.mn.us/biology/Biology1111/animations/enzyme.swf

What role do enzymes play in the textile industry?

Since enzymes quicken the rate of chemical reactions, they also help to quicken the amount of time necessary to make products such as jeans. external image denim.jpg The process of making jeans is as follows: sizing, weaving, desizing, dyeing, finishing.

1. Sizing. In the textile industry, size is a gelatinous substance used to stiffen fabrics such as denim. It is applied to the warp threads to prevent the threads from snapping when undergoing the weave process. Usually a size is made of starch or its by-products, which can be broken down by enzymes such as amylase.

2. Weaving. On the loom, the weft threads are fixed to the loom while the warp threads are passed over or under the fixed threads in order to create a fabric. Denim jeans are usually made from a sized yarn and woven in a specific manner. In denim, warp threads pass under two or more weft threads to create a diagonal weave and the sturdy denim feel. After weaving, the size on the warp threads must be removed in order for the next two steps of the process to have any effect.

3. Desizing. To remove the size and allow jeans to be dyed, factories used to treat their denim with acids, alkali or oxidising agents, but now use enzymes like amylase because they break down starch much faster than the aforementioned chemicals. Desizing also adds a certain softness to the denim while maintaining its durability. Amylase solutions are applied to the denim and break down the starch-based size, allowing fabrics to be dyed. Manufacturers changed to enzyme based solutions because they are quick, can withstand high temperatures, are environmentally friendly, and do not damage the fabric while removing the size. In addition to desizing, some companies bio-polish their denim, which is the process of ridding denim of the small, uneven fibers that protrude from the fabric surface. To do this, cellulase is used; it breaks down fructose and glucose, and the advantages of using it include low colour loss, permanently soft feel, increased absorbency and breathing, and overall look of the fabric, since this enzyme is also used to fade jeans.

4. Dyeing. Meanwhile, when jeans are dyed, the dye does not always penetrate the entire string, leaving a core of yellowish-white. This core is the white part of jeans seen in frayed looks. At times, only the warp threads are dyed, which is why some jeans flaunt both white and blue threads. After this process is finished, jeans are ready to be given individual flair and a uniquely faded look.

5. Finishing. Up until now, the jeans have gone through the same procedure, and it is during finishing that jeans are betrothed their own colour and personality. Formerly, jeans were sanded roughly with pumice stones ( stonewashing), placing the stones and fabric in a rotating washing machine to achieve the faded look. However, since pumice stones are volcanic rock, they are strip-mined and therefore not very environmentally friendly. In addition, a small amount of enzyme can do the same job as several kilograms of pumice stones, plus laundry machines can then contain fewer stones and more garments, increasing productivity. Nowadays enzyme-washes containing cellulase play a role in the final step of production, used either in combination with pumice stones ( river washing) or on its own ( cellulase enzyme wash). Cellulase breaks down the cellulose in the denim threads, made from cotton. The dye from the previous step, coating the threads, comes off with the broken down fibers. Depending on what colour the manufacturer wishes to achieve, the enzyme solution if either a high or low concentration of cellulose and can be stopped by changing the pH of the bath or by heating the water. The denim is then given a final wash before being sent to stores and customers, thanks to help from your friendly neighbourhood enzymes.

For information on the jeans making process, visit the following sites, used extensively to put this page together:
http://wearablesbusiness.com/mag/apparel_denim_legend_lives/index.html — A considerably informative article by Wearables Business magazine, with a thorough briefing on many aspects of denim, such as the history, current fashion, process, and economic market for this immortal fabric.
http://www.cognis.com/framescout.html?/textiles/Denim.htm — From Cognis Textile company, a slightly confusing webpage on the jeans process and various products available to improve the production of denim.
http://www.azcentral.com/style/articles/113005denimfit.html — An article from Phoenix Arizona's local newspage on expensive jeans and why people actually pay for them (hint: it's all in the manufacturing process).
http://www.stalliongrp.com/enzymes.htm — short and simple list, from Stallion Impex dyestuff-manufacturing company, of a few enzymes and their advantageous functions in the textile business.
http://www.enzymeindia.com/textiles.html — Advanced Biochemicals Limited gives its list of products with details of their enzymatic ingredients and usages.

Other Sources on Enzymes

http://www.mapsenzymes.com/Enzymes_Textile.asp — By Maps biotechnology company, which specializes in enzymes, a webpage which includes other parts of the denim process that include enzymes. User friendly in its language and explanations, this is a good place to start for those without an extremely scientific background. Includes information on additional jeans procedures of bleach clean-up and bio-scouring.

http://www.thefabricofourlives.com/FabricSmart/HiTechDenim/ — From a site on fabric care and styles, this page specifically deals with other processes in fading jeans, including the use of enzymes, using pumice stones, and abrasive paper. The descriptions are less explanatory in their use of words, but the rest of the website is also informative and fun to browse.
http://www.thefabricofourlives.com/DenimRules/JeanFinishes/ — a glossary on fabric finishes from the same website.
http://www.thefabricofourlives.com/DenimRules/DenimGuideGlossary/ — a general glossary on terms related to the denim industry.

http://www.specialtyenzymes.com/textiles.shtml — By Specialty Enzymes and Biochemicals Company, a line of manufactured products for use on jeans. Good additional reading, since these are practical, commercial uses of enzymes! Explanations are more complex, but provided chart and points very helpful.

http://www.levistrauss.com/Heritage/History.aspx — By Levi Strauss Jeans company, information on the invention of denim jeans. "Riveting" factoids for everyday conversation about trousers, should the need arise.

http://en.wikipedia.org/wiki/Denim — By Wikipedia. Very general background information on the history of the fabric known as denim and its place in history.

(Page put together by Frances Nan, IB SL Biology Block F)