TEXTILE PRINTING
In textile printing, patterns are applied to fabrics such as clothing, scarves, or towels using a color paste made by mixing dyes. A common method involves placing a dyeing mold or screen over the fabric and pressing the color paste through it to transfer the design. This technique is known as screen printing.
To prepare a suitable color paste for printing, a paste with the right viscosity and fluidity is essential. Sodium alginate is the most widely used paste in this process due to its beneficial properties, including:
1. Fluidity
Fluidity is crucial in textile printing. Sodium alginate solutions maintain excellent flow even at high viscosity, ensuring smooth penetration into the fibers. This results in even dyeing without patchiness. Additionally, alginate-based pastes spread easily on the screen, allowing fine details and intricate patterns to be printed accurately.
2. Compatibility with Reactive Dyes
Natural fibers are often dyed using reactive dyes, which bond chemically with cellulose. While some cellulosic pastes can interfere with dye fixation by reacting prematurely with the dyes, alginate remains inert, ensuring better color yield and print quality.
3. Easy Removal (Desizing)
After printing, the paste must be washed out of the fabric. Alginate dissolves easily in cold water, making desizing more efficient compared to starch-based pastes, which require heating for removal.
4. Reduced Wastewater Impact
Textile dyeing generates large volumes of wastewater that must be treated before disposal. The biodegradability of the printing paste significantly affects wastewater treatment requirements. Synthetic pastes break down slowly, increasing treatment time and costs. In contrast, alginate—a natural seaweed-derived polysaccharide—degrades easily, reducing the environmental burden and making it an eco-friendly choice for textile printing.