Enzyme washing or "bio stoning" is a

textile manufacturing Textile Manufacturing or Textile Engineering is a major industry. It is largely based on the conversion of fibre into yarn, then yarn into fabric. These are then dyed or printed, fabricated into cloth which is then converted into useful go ...

technique in which

cellulase Cellulase (EC 3.2.1.4; systematic name 4-β-D-glucan 4-glucanohydrolase) is any of several enzymes produced chiefly by fungi, bacteria, and protozoans that catalyze cellulolysis, the decomposition of cellulose and of some related polysacchar ...

enzymes are applied to

denim Denim is a sturdy cotton warp-faced textile in which the weft passes under two or more warp threads. This twill weaving produces a diagonal ribbing that distinguishes it from cotton duck. While a denim predecessor known as dungaree has been p ...

. As with traditional

stone washing Stone washing is a textile manufacturing process used to give a newly manufactured cloth garment a worn-in (or worn-out) appearance. Stone-washing also helps to increase the softness and flexibility of otherwise stiff and rigid fabrics such as ca ...

, the intended effect is a faded appearance and softer feel. Because the technique relies on

biotechnology Biotechnology is the integration of natural sciences and engineering sciences in order to achieve the application of organisms, cells, parts thereof and molecular analogues for products and services. The term ''biotechnology'' was first used b ...

, enzyme washing is considered an example of textile bio-processing.

Technique

Mechanism

In the enzyme wash process, cellulases act on exposed

cellulose Cellulose is an organic compound with the formula , a polysaccharide consisting of a linear chain of several hundred to many thousands of β(1→4) linked D-glucose units. Cellulose is an important structural component of the primary cell wall ...

on the cotton fibers, freeing

indigo Indigo is a deep color close to the color wheel blue (a primary color in the RGB color space), as well as to some variants of ultramarine, based on the ancient dye of the same name. The word "indigo" comes from the Latin word ''indicum'', ...

dye from the fabric. The effect achieved by enzyme washing can be modified by using cellulase of either neutral or acidic pH and by introducing extra mechanical agitation by means such as steel balls.

Comparison to other techniques

Advantages

Enzyme washing is considered more sustainable than stone washing or acid washing because it is more water efficient. Residual

pumice Pumice (), called pumicite in its powdered or dust form, is a volcanic rock that consists of highly vesicular rough-textured volcanic glass, which may or may not contain crystals. It is typically light-colored. Scoria is another vesicular v ...

fragments from stone washing demand a lot of water to be eliminated, and acid washing involves multiple wash cycles to produce the desired effect. The

substrate Substrate may refer to: Physical layers *Substrate (biology), the natural environment in which an organism lives, or the surface or medium on which an organism grows or is attached ** Substrate (locomotion), the surface over which an organism lo ...

-specificity of enzymes also makes the technique more refined than other methods of processing denim.

Disadvantages

In enzyme washing, dye released by enzymatic activity has a tendency to redeposit on the textile ("back staining"). Wash specialists Arianna Bolzoni and Troy Strebe have criticized the quality of enzyme-washed denim compared to stone-washed denim but agree that the difference would not be detected by the average consumer.

History

In the mid-1980s, recognition of the environmental impact of stone washing and increasing environmental regulations drove demand for a sustainable alternative. Enzyme washing was introduced in

Europe Europe is a large peninsula conventionally considered a continent in its own right because of its great physical size and the weight of its history and traditions. Europe is also considered a subcontinent of Eurasia and it is located enti ...

in 1989 and was adopted in the

United States The United States of America (U.S.A. or USA), commonly known as the United States (U.S. or US) or America, is a country primarily located in North America. It consists of 50 U.S. state, states, a Washington, D.C., federal district, five ma ...

the following year. The technique has been a subject of more intense scientific study since the late 1990s. In 2017,

Novozymes Novozymes A/S is a global biotechnology company headquartered in Bagsværd outside of Copenhagen, Denmark. The company's focus is the research, development and production of industrial enzymes, microorganisms, and biopharmaceutical ingredients. ...

developed a technique to spray enzymes directly on denim in a closed washing machine system as opposed to adding the enzymes to an open washing machine, further decreasing the water needed for the enzyme wash. The recent revival in acid-washed denim in the late 2010s as well as increased demand for

eco-friendly Environment friendly processes, or environmental-friendly processes (also referred to as eco-friendly, nature-friendly, and green), are sustainability and marketing terms referring to goods and services, laws, guidelines and policies that cla ...

denim voiced on

social media Social media are interactive media technologies that facilitate the creation and sharing of information, ideas, interests, and other forms of expression through virtual communities and networks. While challenges to the definition of ''social me ...

have made sustainable wash techniques such as enzyme washing even more integral to the textile industry.

References

{{Reflist, 2 Textile treatments Jeans