2001 Volume 10 Pages 81-86
The hot air drying process improves the quality of raw silk produced from the cocoons due to proper hardening the sericin. Indian multi-bivoltine cocoons were hot air dried in a batch type hot air drier using different temperature profiles and cooked using open pan and two-pan method of cooking system and reeled to produce raw silk. The characteristics of raw silk indicated that both the drying temperature profiles and method of cooking has significant influence on quality characteristics of Indian multi-bivoltine cocoons. It was observed that higher initial temperature used during drying i.e. 130℃ has significantly improved the quality of raw silk compared to other drying temperature profiles i.e. 120℃, 100℃ and 90℃ in terms of better neatness, cleanness, elongation, cohesion and degumming loss of silk %. Further two-pan cooking method showed a significant improvement in cleanness characteristics compared to open-pan cooking method for hot air dried cocoons. However tenacity characteristics is not significantly affected by drying process. The improvement in the quality characteristics of raw silk produced from different hot air drying temperature profiles is presumably because of hardening of the sericin to the suitable extent. The earlier understanding that higher temperature would denature the sericin and affect the reeling performance does not appear to be true in case of Indian multi-bivoltine cocoons presumably due to the loose shell structure of the cocoons.
