Natural fibers have the potential to replace synthetic fibers for making polymer composites due to their remarkable properties. Polyester is one of the core materiel used for textile and leather due to hydrophobic property. Sisal fibers have high strength among various naturals and can be used as the supporting material for polymers. A detailed experimental study was conducted for the extraction of sisal fiber and composite development. The fibers were treated by using 2%, 6%, and 10% NaOH concentrations within 24, 48, and 72 h soaking time. Composite was made from different sisal to polyester ratios of 20 : 80, 30 : 70, and 40 : 60 (w/w). Mechanical properties such as tensile strength and flexural strength of treated, untreated, and reinforced fibers were determined. Functional groups of both the treated and untreated sisal fibers were characterized using Fourier transform infrared spectroscopy (FTIR). The thermal stability of sisal fiber was analyzed by thermogravimetric analysis (TGA). The optimum tensile strength and bending strength of the composite were found at 44.0 MPa and 50.8 MPa for fiber with polyester ratio of 30 : 70, 6% NaOH concentration, and 48 h soaking time. It is confirmed that treated sisal fiber-reinforced polyester composites have better tensile and bending properties and lower water absorption than untreated fibers.

Natural colorants play a vital role in the production of eco-leather by substituting environmentally hazardous and toxic synthetic dyestuffs. In this study, a natural dye is extracted and optimized from the bark of Ficus sycomorus, a plant species locally known as shola, by designing different combinations of concentration, temperature, and time parameters. A dye extracted from 120 g/l concentration at a temperature of 1000°C for 60 minutes showed the highest absorbance value, and it has been used for further dyeing processes with and without mordant. Properties such as color strength (k/s), Lab values, and color fastness of a dyed leather specimen were measured and analyzed. Oxalic acid mordant-dyed leather samples mordanted with the postmordanting method have revealed the highest k/s value among other experimental samples. Moreover, better color fastness properties were obtained from a leather sample mordanted with oxalic acid. Consequently, a dye extracted from the bark of Ficus sycomorus can be used as a leather dyeing material.

Leather is made from animal hides and skins that have passed through several stages of processing, from soaking to finishing. Unhairing is a crucial processing stage in which hair is removed from the animal hide or skin through open up the hair and it facilitates subsequent operations. The conventional sodium sulfide-based unhairing process generates a high volume of effluent, which accounts for 50 to 70 of the total biochemical oxygen demand (BOD) and chemical oxygen demand (COD) load in the tanneries effluent. This study aimed to investigate the potential of unhairing agents prepared from locally available plants. The research employed qualitative methods. Plant materials are collected, dried, and ground. In different proportions, unhairing extracts were obtained from Phytolacca dodecandra leaves, Cucurbita foetidissima fruits, and Solanum incanum fruits. In the conventional soaking process, plant extracts were applied in various concentrations to sheepskin. The physical parameters of conventionally processed (control) and experimentally treated leather were examined using FTIR, SEM, tear strength, percentage of elongation, and organoleptic tests. The unhairing solution was prepared from a mixture of 0.5 S. incanum extract, 0.5 P. dodecandra extract, 0.6 C. foetidissima extract, and 260g/L lime powder lime, and this solution effectively removed the hair from the sheepskin in both hairs saving and hair burning unhairing process. The study revealed that the sheepskin treated with the plant extracts based on an unhairing agent and the conventional unhairing agent showed a comparable tensile strength (42.3kg/cm and 45.2kg/cm), tear strength (140.1kg/cm² and 143.5kg/cm²), and percent elongation at break (40.2 and 42.3), respectively, which were above the permissible limit for leather production making. According to the study findings, the plant extracts have a good potential for removing hair from sheepskin, and they are eco-friendly and cost-effective compared to unhairing chemicals such as sodium sulfide.