Desizing Agents

Desizing agents remove the warp size u2014 starch, polyvinyl alcohol (PVA),nor carboxymethyl cellulose (CMC) u2014 applied to yarn before weaving, so the fabric cannabsorb scour, bleach, and dye evenly. Two routes do the work: enzymaticndesizing, where amylase hydrolyzes starch into soluble sugars, and oxidative desizing,nwhere peroxide or persulfate degrades both natural and synthetic sizes. Choose thenroute by the size chemistry on the cloth, not by habit.

Amylase is specific. It cleaves starch at roughly 55-70°C within a narrow pHnwindow, which is why a small acetic-acid addition is used to trim the bath to thenenzyme's optimum. Because it targets only starch, it leaves the cotton fiber intact.nSpecify enzymatic desizing when the size is starch-based and fiber strength is thenpriority. The limit is real: amylase does nothing to PVA or acrylic sizes.

Oxidative desizing covers what enzymes miss. Sodium persulfate and hydrogen peroxidenbreak down PVA and mixed-size systems, and an oxidative bath can combine size removalnwith bleaching in one step. The cost is selectivity: a strong oxidizer run too hot orntoo long can attack cellulose and lower fabric strength. For PVA or blended sizes, usenthe oxidative route and hold concentration, temperature, and dwell time to the size load.

• Enzymatic removal of starch size from cotton and cotton-blend greige goods before scouring
• Oxidative desizing of PVA, CMC, and mixed-size warp systems that amylase cannot break down
• Combined desize-bleach baths where oxidative chemistry removes size and whitens in one step
• pH conditioning of enzyme desize baths to hold amylase at its working optimum
• Pretreatment of woven fabric to improve wettability and dye uptake in downstream dyeing

• Amylase enzyme u2014 PubChem
• Sodium persulfate u2014 PubChem
• Hydrogen peroxide u2014 PubChem
• Acetic acid u2014 PubChem