HIGH-STRENGTH SILK FIBER OBTAINED FROM SUPER FINE FILAMENT OF SILKWORM COCOON TREATED WITH BIOACTIVE SUBSTANCES

High strength silk fiber was investigated for practical use. To obtain a fine filament, silkworms were treated with bioactive substances (an ti-JH) and tetramolter silkworms were transformed into trimolter ones. Trimolter silkworm cocoon is smaller than the tetramolter one, filame nt size of smaller cocoon is finer and the filament strength is higher in general. Using the automatic reeling machine (Nissan CT-2), super fine raw silk aimed at obtaining a size of 9.5 d was produced and even ness (U%) and strength of the raw silk were measured. As a result, coc oon width of 16 mm and above was found to be suitable for the reeling machine. Among the cocoons with a cocoon width of 16 mm and above, tri molter race TC14 x MK treated with anti-JH was found to be suitable. T he cocoon filament size was 1.04 denier and the raw silk size deviatio n was low (U%: 4.59%). The strength of the raw silk was 30% higher in comparison to the raw silk of the authorized and distributed silkworm race Asahi x Tokai.