Mechanical Properties of Silk Fabric Degummed with Bromelain

Degumming is the process of removing the sericin or gum from silk yarn. Removing the gum improves the sheen, color, hand, and texture of the silk. Mai 1 silk yarn from Thai hybrid multivoltine Bombyx mori was degummed with commercial grade bromelain and with sodium carbonate. 96.58% of sericin content was removed from the silk yarn in small scale degumming procedure with 2 g/L bromelain and 91.84 % in large scale degumming with 5 g/L bromelain. Scanning electron micrographs of the silk yarn degummed with enzyme showed neither sign of destruction in its morphology nor surface damage. The surface of the yarn degummed with bromelain was smoother than that of the yarn degummed with sodium carbonate. According to the evaluation of its mechanical properties using Kawabata Evaluation System for Fabric, the silk fabric degummed with bromelain showed good tensile strength, better response to bending deformation, higher flexibility, smother feel during bending, and softer and better elastic properties during compression.