Abdullah Al Fariz

The increasing demand for cleaner coloration of synthetic textiles has renewed interest in plant-based dyes; however, limited dye–fiber affinity and shade durability remain major challenges in nylon dyeing. This study developed a mordant-free dyeing process for nylon fabric using Terminalia catappa leaf extract by optimizing extraction pH, dyebath pH, dyeing time, and temperature. Mature T. catappa leaves were aqueously extracted under acidic, neutral, and alkaline conditions, followed by systematic dyeing optimization. The dyed fabrics were evaluated using color strength (K/S), CIELAB color coordinates, standard fastness tests, FTIR spectroscopy, and FE-SEM analysis. Alkaline extraction followed by acidic dyeing produced the highest dye uptake. The optimum condition was extraction pH 11, dyebath pH 3, 120 °C, and 60 min, yielding a maximum K/S value of 21.94 with ΔL, Δa, and Δb values of −54.25, 8.03, and 24.92, respectively. FTIR and SEM results supported possible dye–fiber interaction through hydrogen bonding, electrostatic attraction, and surface/inter-filament dye deposition without obvious fiber damage. The optimized fabric showed very good washing, dry rubbing, perspiration, and saliva fastness, good light fastness, excellent ultraviolet protection, and slightly lower wet rubbing fastness. Overall, T. catappa leaf extract offers a promising mordant-free route for durable nylon coloration.

The conventional reactive dyeing process for cellulosic fibres, such as cotton, is fraught with challenges, particularly concerning the hydrolysis of dyes and the resultant-coloured sewage, which complicates wastewater treatment. This study introduces an innovative solution by integrating sorbitol into the dyeing process. By varying the proportions of sorbitol mixed with water, the researchers aimed to enhance dyeing efficiency while mitigating environmental impacts. The experimental procedure involved pre-treating knitted cotton fabric and preparing a dyeing liquor that combined sorbitol and water. Dyeing was performed using an infrared sample dyeing machine, which allows for more controlled and efficient dye application. To evaluate the results, colour strength and colour measurement characteristics (CMC) in the post-dye liquor were analysed using a Data Color 650 spectrophotometer. The findings revealed that fabrics dyed with sorbitol not only displayed higher chroma values but also resulted in a reduction of dye strength in the post-dye liquor. This indicates a significant decrease in the hydrolysis of reactive dyes, leading to lower costs associated with sewage treatment. Furthermore, colourfastness tests performed on the dyed fabrics demonstrated excellent performance, underscoring the effectiveness of this unique dyeing approach. Future research will focus on applying this method with various classes of reactive dyes in order to explore their performance based on different reactive groups to further enhance the non-aqueous medium dyeing of cotton in textile dyeing processes.

Purpose: This study uses bio-coatings generated from banana peels and bio-composites manufactured from waste fabric to explore creating and assessing new flame-retardant materials. Design/Methodology/Approach: Polyvinyl acetate (PVAc) was used as a binder with banana peels, a readily available organic waste, to create bio-composite materials and flame-retardant fabric (FRF) coating. The 45° Burning Test, BS 4790 Fire Test (Hot Nut Test), Direct Metal Heat (DMH) Test, Welding Spark Test, Direct Heat Test, and Chemical Resistance Testing (H₂SO₄) were among the tests used to evaluate the samples' fire retardancy. Findings: During the 45-degree burning test, untreated cloth showed poor resistance, lighting after 23 seconds, whereas FRF required 93 seconds, and flame-retardant composite (FRC) demonstrated the best flame resistance, igniting after 315 seconds, followed by plywood at 245 seconds. Additionally, FRC showed outstanding fire resistance, endured exposure to strong sulfuric acid without suffering any harm, and remained unaffected for 600 seconds. Conclusion: The overall findings show that, compared to untreated fabric and plywood, the bio-composites and bio-coated textiles demonstrated noticeably improved flame resistance. The bio-composites demonstrated outstanding performance with prolonged resistance to ignition and prolonged exposure to direct heat and chemical conditions, suggesting their potential as cost-effective and ecologically friendly alternatives to synthetic materials in fire safety applications.