Review: Potential use of plant proteins and feather keratin as sizing agents for polyester-cotton

This review assesses the potential of using plant proteins (wheat gluten and soy proteins) and chicken feather keratin as sizing agents for polyester/cotton (P/C) fabrics. Sizing (slashing) is a critical and essential process required for weaving fabrics. Poly(vinyl alcohol) (PVA) is a traditional size for P/C yarns since PVA readily dissolves in water, provides good sizing performance, and is easily desizeable. However, PVA released from textile effluent treatment affects water organisms. Protein-based sizes required higher percent add-on to provide strength similar to PVA, but had excellent desizing, even at room temperature using low liquor ratios. Similarly, protein-based sizes degraded easily in activated sludge with COD and BOD₅ values well within the prescribed limits. Plant proteins and feather keratin show promise to replace PVA for sizing P/C fabrics.