Enzyme washing or "bio stoning" is a textile manufacturing technique in which cellulase enzymes are applied to denim. As with traditional stone washing, the intended effect is a faded appearance and softer feel.[1] Because the technique relies on biotechnology, enzyme washing is considered an example of textile bio-processing.[2][3]

Technique

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Mechanism

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In the enzyme wash process, cellulases act on exposed cellulose on the cotton fibers, freeing indigo dye from the fabric.[4] 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.[1]

Comparison to other techniques

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Advantages

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Enzyme washing is considered more sustainable than stone washing or acid washing because it is more water efficient. Residual pumice fragments from stone washing demand a lot of water to be eliminated, and acid washing involves multiple wash cycles to produce the desired effect.[5] The substrate-specificity of enzymes also makes the technique more refined than other methods of processing denim.[1]

Disadvantages

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In enzyme washing, dye released by enzymatic activity has a tendency to redeposit on the textile ("back staining").[4] 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.[5]

History

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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 in 1989 and was adopted in the United States the following year.[6] The technique has been a subject of more intense scientific study since the late 1990s.[1] In 2017, Novozymes 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.[7] The recent revival in acid-washed denim in the late 2010s as well as increased demand for eco-friendly denim voiced on social media have made sustainable wash techniques such as enzyme washing even more integral to the textile industry.[5]

See also

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References

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  1. ^ a b c d Patra, A.K.; Madhu, Amit; Bala, Neeraj (2018). "Enzyme washing of indigo and sulphur dyed denim". Fashion and Textiles. 5. doi:10.1186/s40691-017-0126-9.
  2. ^ Mosjov, Kiro (2014). "Trends in Bio-Processing of Textiles: A Review". Advanced Technologies. 3 (2): 135–138.
  3. ^ ENZYME WASHING INFORMATION
  4. ^ a b Bhat, M.K. (2000). "Cellulases and related enzymes in biotechnology". Biotechnology Advances. 18 (5): 355–383. doi:10.1016/S0734-9750(00)00041-0. PMID 14538100.
  5. ^ a b c Trotman, Samuel. "Future of Wash: Sustainable Solutions for Stone and Acid Wash in the Denim Industry". Denim Dudes. Retrieved 14 November 2020.
  6. ^ Marre, Kathleen. ""Stone" Washing Jeans: Cellulases". IUPUI Department of Biology.
  7. ^ "Enzymes make your jeans less thirsty". Novozymes.