Sustainable Enhancement of Flame Retardancy in Industrial Protective Textiles Using Calcium Alginate Hydrogel Treatment

This study investigates the sustainable enhancement of flame retardancy in industrial protective textiles via surface treatment using calcium alginate hydrogel. Bamboo and polyester microfiber-based textiles and their 50:50 blends were created in plain 1/1 and twill 2/2 weaves to examine the synergistic effect of fiber content and fabric structure towards fire resistance. The samples were then treated with 10% sodium alginate solution and subsequently underwent ionic crosslinking with calcium ions to form a stable calcium alginate hydrogel coating on the surface of the fabric. The treated samples were characterized in a systematic manner in terms of areal density, thickness, char length, and flammability, for example, Limiting Oxygen Index (LOI) and vertical flame tests.Results revealed that twill 2/2 weaves with increased percentage of bamboo showed increased weight, thickness, and fire retardancy based on increased hydrogel absorption values and innate bamboo fiber characteristics. The blended fabrics (50% bamboo : 50% polyester microfiber) also had enhanced flame-retardant properties, which were described through increased retention of fire-retardant material as well as the ability to suppress the flame spread by sequestration of free radicals within the gas-phase combustion zone. Char length and LOI analysis confirmed the significant improvement of fire resistance by the hydrogel coating, while fabric structure and fiber composition played a significant role in gaining optimised performance.These findings validate a self-evident correlation between the building of the fabric, the material composition, and the flame resistance, highlighting that calcium alginate hydrogel treatment is a sustainable, green, and efficient method to attain enhanced protection of industrial protective wear. The study highlights the potentiality of natural polymer-based finishes in designing resistant textiles to the challenging conditions of extreme temperature industrial settings, offering an environmentally friendly alternative to conventional chemical-based flame retardants.