Investigation of Colourimetric Characteristics and Antifungal Activity of Wool Felt Dyed with Natural Extracts

This study investigates the eco-friendly modification of wool felt using natural plant extracts – black tea (Camellia sinensis), sage leaves (Salvia officinalis), and oak bark (Quercus cortex) – with alumino-potassium alum as a mordant, aligning with circular economy principles in light industry. Modified materials were evaluated for CIELAB color characteristics, air permeability (ISO 9073–15:2007), rubbing fastness (ISO 105-X12:2016), and antifungal activity against Candida fungi (ISO 13629–2:2014). Colorimetric analysis showed deep pigment penetration compared to the control (L* = 79.80, a* = -0.28, b* = 9.85). Camellia sinensis caused the most intense darkening (ΔL*=-14.72) with a deep brownish-red tone (a* = 7.35, b* = 22.80). Salvia officinalis produced warm greenish-yellow tones (b* = 22.71), while Quercus cortex provided uniform darkening (L* = 73.65). All samples exhibited excellent dry and wet rubbing fastness (4–5 points) and maintained stable air permeability (518.6-528.8 mm/s), preserving the wool’s porous matrix. Microbiological tests revealed that Camellia sinensis ensured 100% fungistatic purity, Quercus cortex provided high inhibition, and Salvia officinalis maintained moderate biostability. This green biotechnology offers a viable alternative to toxic synthetic finishes. These results are highly applicable for manufacturing high-tech, eco-friendly felt footwear and accessories.