Biopolymer Function
Natural polysaccharide thickening agents extracted from brown seaweed provide precise viscosity control in textile print formulations. Sodium alginate thickener serves as the primary rheology modifier for printing reactive dyes on cotton, linen, and viscose substrates. High water solubility allows easy washing out after dye fixation, leaving a soft fabric hand.
Reactive Compatibility
Unlike starch or cellulose-based thickeners containing primary hydroxyl groups, alginate molecules do not react with reactive dye molecules under alkaline steaming conditions. Using sodium alginate thickener prevents covalent bonding between the dye and the thickener polymer backbone, ensuring that all available dye fixes to the cotton fiber rather than getting trapped in the paste residue.
Rheology Performance
Dissolving refined alginate powder in cold water yields smooth, non-tacky print pastes with excellent shear thinning properties. Formulations with sodium alginate thickener pass easily through rotary screen meshes under squeegee pressure while maintaining crisp pattern outlines on woven cotton lawn. Washing boxes strip the unreacted thickener film effortlessly during post-steam open width washing.
Chemical Boundary
Hard water containing high calcium ion concentrations crosslinks alginate molecules, forming insoluble calcium alginate gels that clog print screens. Synthetic acrylic thickeners replace alginate when printing disperse dyes on polyester under high-temperature fixation conditions.
