Sizeings

Sizeings are substances applied to warp yarns in weaving to improve processing efficiency and fabric quality. They form a protective film that reduces abrasion, minimizes yarn breakage, and helps maintain dimensional stability during weaving. The term sizeings covers a range of formulations used across fiber types, and a desizing step is typically required to remove the film before dyeing or finishing.

Historically, sizing began with natural starches and later evolved with industrialization. Starch-based sizes were common in cotton fabrics, while linen and wool used different formulations. In the late 20th century, synthetic polymers such as polyvinyl alcohol (PVA) and carboxymethylcellulose (CMC) gained prominence due to improved performance and easier removal. Modern sizing strives to balance weaving efficiency with fabric hand, dyeability, and environmental impact.

Composition and methods vary, but common sizeings include natural starches (corn, wheat), cellulose derivatives (CMC), alginates, and synthetic polymers (PVA, polyacrylates). Additives such as lubricants, surfactants, and crosslinkers may be included to enhance slipperiness, bonding, or water resistance. Application methods include pad-dry-cure and beam or roller sizing, with solids content and film-forming characteristics tailored to the fiber and end-use.

Desizing, the removal of sizeings after weaving, is essential for uniform dyeing and finishing. Enzymatic desizing targets starch-based sizes; chemical desizing uses acids or oxidizers, and alkali can be used for certain synthetic sizes. Environmental considerations drive the development of biodegradable and low-energy sizing systems, as well as closed-loop wastewater treatment.

Sizeings vary by fiber and process, and they remain a key factor in weaving performance and fabric quality.