Enzymatic desizing

The pH of the desizing bath is maintained by adding acid or alkali. The effects of pH and temperature on enzyme activity are shown in Figs. 3-3 and 3-4 respectively. However storing the enzyme at a fixed temperature shows that the activity steadily decreases with time (Fig. 3-5). In general, changes in pH, tem- 

Sometimes sodium or potassium chloride (0.18-1.0%) is added to the desizing bath for pancreative enzymes to get its full activity. For malt a-amylase calcium ion is effective and sequestering agent must be avoided in the desize bath. These salts are particularly used for desize mixture by affording heat protection to enzyme, increased stability of the enzyme and efficiency. On the other hand, heavy metal ions such as copper, iron etc. may combine with enzyme and inhibit its activity [8]. Sometimes hydrocarbon solvents such as xylene (50 ml/1) along with suitable emulsifier (4 g/1) are also added to facilitate removal of waxy components of the size. 

Following the digestion period, a hot water wash, with or without subsequent alkaline scour, is required for complete removal for the size that has been solubilised by the enzymes. 

---

Enzymatic desizing is one of the oldest nonfood appHcations of commercial amylases. Another type of enzyme, microbial ceUulases, has developed within the textile iadustry as a tool for fabric finishing, ia particular for denim garment finishing. CeUulases can achieve the fashionable worn look traditionaUy obtained by the abrasive action of pumice stones, ie, stone-washing. 

If LEONIL EB is used, a separate enzymatic desizing process can usually be omitted, thus effecting considerable savings in time, energy and water. 

In enzymatic desizing, the time, temperature and pH of the desizing bath is well controlled. Furthermore, the action of enzyme is restricted only on the sizes present on the fabric and thus degradation of the fibre due to enzymatic desizing is few and... 

Biolase Brands. [Hoechst Cdanese Hoechst AG] Bacterial amylases enzymatic desizing agent... 

Yerozyme. [Miles/Oiganic Prods.] Enzymatic desizing agent. 

Mori, T., Sakimoto, M., Kagi., T., and Saki, T. (1999). Enzymatic desizing of pol winyl alcohol from cotton fabrics, I. Chem. Tech. Biotech.. 68(2), 151-156. 

Properties Wh. tanslucent liq. mild odor water-disp. flash pt. > 100 C pH 5-7 UseLevei 0.2-0.4% (enzymatic desizing) 0.5-1.0% (scouring knits)... 

Fukuda et al used a new approach for the enzymatic desizing of starched cotton cloth. Sizing is required to prevent abrasion, fluffiness, and cutting of the warp during the weaving... 

Fukuda, T Kato-Murai, M Kuroda, K Ueda, M Suye, S. Improvement in enzymatic desizing of starched cotton cloth using yeast codisplaying glucoamylase and cellulosebinding domain. Appl Microbiol Biotechnol, 2008, 77, 1225-32. 

---