The physical fibre properties of Gonometa postica after degumming the cocoons with different methods

Abstract

Silk fibres from Gonometa postica were degummed with different, not yet considered, environmentally-conscious methods to conserve energy.  The agents used were vermicompost, distilled water, catholyte, and Eucalyptus oil. The results were compared to a control, Orvus paste, which is currently in use as a chemical degumming agent. The physical properties of the silk fibres that were evaluated in this study included weight loss determination, degumming efficiency and scanning electron microscopy.  The results indicated that the weight loss of G. postica fibres ranged from 27 to 41% over a time period of 10 days for the different methods evaluated.  Orvus paste and Eucalyptus oil, catholyte and Orvus paste caused the greatest weight loss indicating the best sericin removal. Distilled water and Eucalyptus oil were the least successful in sericin removal, delivering a weight loss of less than 30%.  The SEM micrographs indicated some sericin remnant still present on the fibres. Catholyte set a better standard for performance.  It was concluded that catholyte, vermicompost and distilled water can be recommended as alternatives to the chemical Orvus paste as degumming method for G. postica wild silk