Desizing
Desizing is the reverse process of sizing. It is necessary to remove the size paste from the fabric after weaving. It is nothing but the washing action that is able to remove possibly all the ingredients of size paste from warp ends.
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| Desizing process |
Necessity of desizing
The varied characteristics of yarn are limited by size.
Sizing has
an impression on the subsequent properties:
- Absorbency - the power of yarn to soak up is reduced as a result of size. As a result, yarn is going to be unable to soak up any chemical or colour during subsequent processing. further, as inconsistent dyeing, bleaching, printing, and other processes occur.
- Stiffness- Because the stiffness of the yarn is enhanced as a result of size, the material is difficult to wear or use.
The size, which is added to the grey cloth in an exceedingly weaving preparatory procedure called sizing, contains inherent imperfections still as size is applied to the material to enable weaving Substances are added for specific goals, like greater weave-ability, increased strength, and so on, may well be classified as undesirable matter. As a result, for correct wet processing, this undesired size must be reduced through desizing.
The desizing of the material is finished in two ways: hydrolytic and oxidative. Hydrolytic methods cause the starch to be hydrolyzed, while oxidative methods cause the starch to be oxidized during the desizing process. Enzymatic desizing, alkali desizing, acid desizing, and decay steeping are samples of the hydrolytic type, whereas chlorine, chlorite, and bromite are samples of the oxidative kind.
Sizing components accustomed to cotton warp thread to bolster it before weaving, like starch, carboxylic methylcellulose (CMC), polyvinyl alcohol (PVA), vegetable oils, tallow, and others, make
the material unsuitable for dyeing. Although warp sizing may be a vital procedure for the weaver, the dimensions within the grey cloth impede chemical reactions. As a result, to successfully wet the process, this undesired size must be reduced.
The object of Desizing
Desizing is the process of removing the dimensions that are given to grey fabric during the weaving process, allowing the material to be scoured and bleached properly.
Poly Alpha glucopyranose, which contains both straight-chain and branched-chain polymers, is the most prevalent constant size i.e. starch chemically.
Both of those polymer forms are water-insoluble, but they will be made soluble by hydrolyzing long-chain molecules into shorter ones. As a result, starch is often hydrolyzed or de-escalated overtime under the proper conditions.
The stages of hydrolysis are shown below.
[C6H12O5]n → [C6H12O5] → [C6H22O11] → C6H12O6
Starch → Dextrin → Maltose → Glucose
(Higher molecular. (Low molecular weight ). Weight)
Desizing could be an action that may be controlled in terms of speed. For example, if the desizing liquor is powerful, the method is completed quickly and desizing is often worn out never-ending manner; however, if relatively weak solutions are used, the method will take longer and desizing will be exhausted in batches.
Because the scale mixture usually contains other ingredients that the starch acts as a binder, the bulk of them are readily released and removed when the starch is hydrolyzed and washed off for efficient sizing operation, the added matter is chosen so 85 to 90% of the dimensions are removed during desizing so that desizing is completed uniformly.
Amylose and amylopectin are the 2 main components of starch. the share of amylose and amylopectin changes according to the source from which they were extracted. It's glucose that hasn't been polymerized.
Both amylose and amylopectin are water-insoluble and have an open chain versus an open-chain structure.
Strach ( C6H12O5 ) → Amylose.
Amylopectin (Straight chain) → (Branched-chain)
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| Amylose for resizing |
Structure of amylose (linear, unbranded structure)
Structure of amulo pectin(branched structure)
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| Amylo pectin for desizing process |
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| Amylo pectin for desizing process |
Questions -
- What is desizing?
- What is the necessity of desizing?
- What are the objectives of desiing?
References
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Arputharaj, A., Raja, A. S. M., & Saxena, S. (2016). Developments in sustainable chemical processing of textiles. In Green Fashion (pp. 217–252). Springer Singapore.
Cenite, M. (2015). Google Books. In The SAGE Guide to Key Issues in Mass Media Ethics and Law (pp. 847–858). SAGE Publications, Inc.
Chemicals used in textile processing. (2013, January 10). OEcotextiles. https://oecotextiles.blog/2013/01/10/chemicals-used-in-textile-processing/
Chemistry of textile manufacturing. (2014, April 29). Worldofchemicals.com; Worldofchemicals. https://www.worldofchemicals.com/448/chemistry-articles/chemistry-of-textile-manufacturing.html
Get to know about chemical processing of textile materials. (2022, May 10). ECHEMI. https://www.echemi.com/cms/640314.html
Kan, C.-W. (2015). Plasma treatments for sustainable textile processing. In Sustainable Apparel (pp. 49–118). Elsevier.
Textile School. (2010, November 10). Fabric wet processing techniques. Textile School. https://www.textileschool.com/343/fabric-wet-processing-techniques/
textileblog. (2020, June 19). Stages of wet processing in textile industry. Textile Blog. https://www.textileblog.com/stages-of-wet-processing-in-textile-industry/
Vigo, T. L. (2014). Textile processing and properties: Preparation, dyeing, finishing and performance: Preparation, dyeing, finishing and performance (1st ed.). Elsevier Science & Technology. https://www.elsevier.com/books/textile-processing-and-properties/vigo/978-0-444-88224-0?country=GB&format=print&utm_source=google_ads&utm_medium=paid_search&utm_campaign=ukshopping&gclid=CjwKCAiAhqCdBhB0EiwAH8M_Gn3kr_d2paqVzccxckWobOsLcwl0cD_Mu6vA5I-eqFARiZwx32eUOxoC-LMQAvD_BwE&gclsrc=aw.ds
(N.d.). Textilelearner.net. https://textilelearner.net/flow-chart-of-textile-wet-processing/
Babu, S. (n.d.). Textile Adviser. Textileadvisor.com. from https://www.textileadvisor.com/2021/12/fabric-desizing-process-types-of.html
Desizing. (n.d.). Kemin. from https://www.garmonchemicals.com/en/textile-chemicals/garment-denim-finishing/enzyme-desizing
Landage, S. M. (2022). Biotechnological approaches in desizing of textile materials. In O. L. Shanmugasundaram (Ed.), Applications of Biotechnology for Sustainable Textile Production (pp. 47–73). Elsevier.
Madhu, C. (n.d.). TEXTILE CHEMROSE. Blogspot.com. from https://textilechemrose.blogspot.com/2015/12/desizing.html
Process of cotton Textile Materials desizing. (2013, September 12). Fibre2fashion.com; Fibre2Fashion. https://www.fibre2fashion.com/industry-article/7064/problems-in-desizing-cotton-textile-materials
Trivedi, Y. (2021, May 9). Textile Desizing process. Textilesphere.com. https://www.textilesphere.com/2021/05/desizing-textile.html
Further reading,
Part 2 Desizing process reactions - Hydrolytic and Oxidation method
Part 3 Three chemicals that carried out desizing
Part 4 Rot steep and Acid steep methods for desizing
Part 5 Alkali desizing
Part 6 Hydrolytic desizing
Part 7 Desizing with the help of the Enzymes
Part 8 Continuous desizing process (Winch and J-box)
Part 9 Desizing of polyester-cotton blends
Part 10 Padroll and padsteam desizing
Part 11 Novel desizing
Writer - Rushikesh Patil (Textile Engineer)
