Desizing

What is desizing in textile? Desizing removes warp size—starch, PVA (polyvinyl alcohol), or blended formulations applied on the sizing machine—from greige cloth so water, dye, and chemistry penetrate evenly. Weaving needs the size for strength; dyeing needs it gone.

Where desizing sits in preparation

1. Singeing — clean the face
2. Desizing — remove warp size
3. Scouring — remove oils, waxes, residues
4. Bleaching (where specified) — even base color

Skip desizing and scour chemistry cannot reach the fiber uniformly—patchy dye follows no matter how good the dyehouse is.

Desizing methods (match to the size)

• Enzyme — selective for starch sizes; mild conditions, needs time/temperature control
• Alkali — broader, suits synthetics and blends; harsher on hand if overdone
• Oxidant — fast with partial bleaching effect; can degrade fiber when misapplied
• Hot water — only for water-soluble sizes; a soak, not a universal route

Name the size chemistry first. Starch responds to enzyme; PVA wants alkali or oxidant chemistry.

What to put on the PO

• Size chemistry if known, or a size spot-test requirement
• Absorbency target after desize (water-drop seconds)
• Downstream route: scour, bleach, dye, print, or finish
• Lab check on the actual construction before bulk

On Weaverine polyester programs, desizing is a preparation note on the greige-to-finish route—write the size type and absorbency target, not the word desizing alone.