Some of us spend hours deciding what we are going to wear the next day, while others...not so much. You may be one of those who, after careful planning and matching, decide to put on a trendy shirt, a pair of stylish jeans, accessories and ta-da! Or, you are one of those who wakes up ten minutes before school starts and throw on some random sweatshirt with a pair of completely uncoordinated pair of jeans you've had since middle school. No matter which one you are or how fashionable you are, there is in common with the two pairs of jeans. Regardless of the color or style, it is very likely that your jeans had undergone some wash treatment in the making to the soften the originally hard denim fabric.

The History of the Production of Jeans

In the old days, pumice stones were added into large washing machines to make the freshly dyes jeans look worn or faded. The pumice stones were like sandpaper that removed some of the dye from the surface of the jeans, revealing the orginial color of the material. Howeexternal image hollister%20destroyed%20jeansbig.jpgver, the quality of these "stone washed" jeans were hard to control. Very often the quality of the product and life of quipment were significantly reduced, increasing the cost of production. This method also induced some environmental issues, which furthermore added to the cost of production of jeans. Questions such as: "Are prices of jeans going to skyrocket?" or "Will we have to choose between fashion or the environment?" were asked. But don't worry, because Biology saved the day! A technique called "biostoning" was discovered and this method gave the products a much more controlled and uniformed appearance. What exactly was used in biostoning? Enzymes were used to create the worn and faded look of jeans AND they soften the fabric.You may not know this, but much of the everday objects that we are so familiar with used enzymes. Enzymes to tenderize meat, to make syrup, to make cheese, in washing power, or to soften and fade denim.

Enzyme Used in Jeans

Enzymes are a type of protein in living organisms that aid or speed up the process of transforming substances into other substances.
Many types of enzymes are used in the textile industry and each has its own unique properties which give enhance the flexibility of fashion designers. They would no longer have to fear that the mini logos on buttons, or leather labels destroyed during the process of "stone washing".
Cellulase: digests cellulose, which is the main component of cotton and other natural plant fibers. Cellulase is used to smooth the fabric, removing knots in cloth that make it rough. It binds to the exposed cellulose on the exterior of each cotton fiber and break some of the molecular bonds. The process can be stringently controlled so that only the dye particles are loosened from the denim surface while the interior of the cotton fibers are left intact. Ta-da! A pair of faded, fashionable jeans are made!
◦ An advantage of using cellulase is that the non-cellulos fibers such as nylon and polyester wouldn't be affected and would still remain colorful after the wash.
◦ Just in case you weren't sure what cellulose is, it is a long glucose polymer used as structural support in plant cell walls. Human cannot digest cellulos, but fungi and bacteria can. Cellulase was first extracted from a type of fungus called Trichoderma reesei, then it was put into bacteria for mass production.
Note: words ending in -ase usually means the molecule is an enzyme.

Advantages of Biostoning

Biostoning is so far the most economical and environmentally friendly way to handle denim.
  • Waste, pollution, quality variability, and imperfections are all reduced. And unlike pumice or acid, which get used up during the wash and may even cause environmental issue, enzymes can be recycled.
  • A small dose of enzymes can replace several dozen pounds of pumice stones. So productivity can be increased by 30-50% because more jeans can now fit in the washing machine instead of piles of pumice stones.
  • There time-consuming and expensive task of removing stone fragments from the jeans after the wash is eliminated.
  • There is also no pumice dust in the atmosphere of the factory to endanger employee health or pumice sediment to clog drains.




This page is made by Alice Wang, IB BIology SL block F