Modified Tapioca Starch (Textile Sizing Grade)

About This Product

Warp sizing is the operation that makes weaving possible. Before a warp sheet goes to the loom it is coated with a polymer film that binds the protruding fibres to the yarn body and gives the surface enough abrasion resistance to survive several thousand cycles through the heddles and reed. Starch has been the dominant sizing agent for as long as there have been power looms, and modified tapioca starch is specified where the film needs to be flexible as well as strong. The case for tapioca over maize in the size box rests on film character. Tapioca has a low amylose content, so the film it forms is less brittle and more extensible than a maize film of the same add-on. On a high-speed air-jet or rapier loom that matters: a brittle size shatters off the yarn as dust, loses its protective value part way down the warp and fouls the shed. A tapioca film flexes with the yarn and stays where it was put. Tapioca also has very low lipid and protein content, so the size liquor foams less and leaves no scum in the size box, and its lower gelatinisation temperature cuts the steam load on the cooker. The starch is modified rather than native because a native paste is far too viscous to run at useful solids. Oxidation and acetylation both cut viscosity while improving adhesion to cellulose, which lets the size box run at a concentration that gives the required add-on in a single dip without the liquor turning to gel as it cools. Desizing is the other half of the specification. A size that will not come off cleanly carries through to dyeing as resist marks and uneven shade. Modified tapioca size is readily removed by conventional enzymatic desizing with bacterial alpha-amylase, and because it is a starch it leaves a biodegradable effluent load rather than the persistent synthetic polymer load of a PVA size, which increasingly matters to a mill under discharge consent. It is used for sizing cotton and cotton-blend warps, as a thickener in pigment printing pastes, and in textile finishing. Bio Green Chem supplies textile sizing grade modified tapioca starch in 25 kg bags and jumbo bags. Viscosity at working concentration, film strength and elongation, adhesion, degree of modification and ash are confirmed on the agreed specification and on the batch certificate of analysis.