[in Japanese]

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  In order to study the properties of the raw silk and fabric which were reeled from cocoons reared on all instar artificial diet, the authors investigated the physical properties. The results are summarized as follows :
  1. Tenacity elongation and Young's modulus of the raw silk made from fresh cocoons were higher than the values of raw silk made from dried cocoons, but in the case of degummed silk, these values showed the opposite tendency.
  2. The KES values of KOSHI(Stiffness), HARI(Anti-drape stiffness) and SHINAYAKASA(Flexibility with soft feeling) of the fabric made from fresh cocoons and dried cocoons showed the distinct differences, that is, the texture of fabric made from fresh cocoons is softer than that of dried cocoons.

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[in Japanese]

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  In order to simulate the slugs occurrence states on the fabric by measuring the slugs on the dupion silk in the silk reeling process, the authors formed the slugs measurement apparatus by laser, and examined the analysis method for detecting the slugs from the measurement wave forms indicating the thickness of dupion silk. As a result, it was confirmed to be able to infer the slugs occurrence states on the fabric by actual measurement or sampling measurement of the slug length and the distance between slugs on the dupion silk.

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[in Japanese]

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[in Japanese]

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[in Japanese]

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[in Japanese]

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[in Japanese]

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  Hot air drying of multi-bivotline cocoons evaporates the moisture in the pupa depending up on the temperature profiles used for the drying. Both the temperature profiles and the duration of drying were found to have significant effect on the degree of drying of hot air dried of cocoons. The studies further indicated that higher the initial temperature used for drying, less degree of drying and maximum weight loss occurs during the initial two hours of drying, later it stabilizes as the moisture present in the pupa decreases. Compared to bivotline cocoons, the degree of drying of multi-bivoltine cocoons is further reduced which may be attributed to the porous structure of the Indian cocoons.

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  The process of hot air drying of cocoons facilitates evaporation of moisture from the cocoon shell and pupa there by hardening the sericin to the suitable extent. Based on the temperature profiles used in the drying process, the degree of drying and hardening of sericin varies. 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. Studies indicated that both the temperature profiles and method of cooking has significant influence on reeling performance of Indian multi-bivoltine cocoons. It was observed that higher initial temperature used during drying i.e. 130℃ has significantly better reeling performance than 120℃, 100℃ and 90℃ in terms of better reelabiity, raw silk %, lower waste % and sericin loss %. Further two pan cooking method showed a significant improvement in reeling performance compared to open pan cooking method for hot air dried cocoons. The improvement in the reeling peformance of hot air drying profile 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.

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  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.

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