The Impact of Cashew Nut (Anacardium occidentale) Testa Tannin Feeding Ratio on the Chemical and Mechanical Characteristics of Leather Tanned from Cowhide, Goatskin and Sheepskin

In recent years, there has been a growing interest in exploring natural alternatives to synthetic tannins, driven by concerns over sustainability and environmental impact. Natural tannins offer several advantages, including biodegradability, renewability, and lower environmental impact compared to synthetic chemicals. Among the natural tannins under investigation, cashew nut testa tannin has emerged as a promising candidate due to its abundance, renewability, and potential benefits in leather tanning applications. This research investigated the impact of varying feeding ratios of cashew nut testa tannin on the chemical and mechanical characteristics of leather tanned from cowhide, goatskin, and sheepskin. The objective was to determine how different concentrations of cashew nut testa tannin influence the quality and performance of the leather. Leather samples were prepared using different feeding ratios of cashew nut testa tannin and subjected to a series of chemical and mechanical tests. The results indicated that the absorption of tannin and the resultant chemical stability varied with the type of hide or skin, with each exhibiting unique optimal ratios for tannin uptake. Higher tannin ratios generally improved the tensile and tear strength of the leather across all types, with significant enhancements noted in goatskin and sheepskin. However, an increase in tannin ratio reduced the flexibility of cowhide, while goatskin and sheepskin maintained adequate flexibility. The study demonstrates that cashew nut testa tannin is an effective and sustainable tanning agent, capable of producing quality leather. The findings suggest that the leather industry can utilize cashew nut testa tannin to enhance leather properties, with potential customization of tannin feeding ratios to meet specific performance requirements. Further research is recommended to explore long-term durability and economic viability on a commercial scale. This study contributes to the development of eco-friendly tanning practices and provides insights into optimizing the use of cashew nut testa tannin for various types of leather.