[in Japanese]

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  The process of cooking using pan and conveyor methods were studied to find out its influence on reeling performance and quality of raw silk produced from bivoltine cocoons. The conveyor cooking of cocoons found to uniformly soften the sericin thereby improving the reeling characteristics viz. groping end efficiency, reelability percentage, raw silk percentage, raw silk recovery percentage and reducing the waste percentage on silk weight. The quality characteristics viz. neatness percentage, cleanness percentage and cohesion were also improved when the cocoons are cooked using conveyor cooking machine. The tenacity and elongation of raw silk did not change significantly by both the methods of cooking. This result clearly revealed that conveyor cooking of bivoltine cocoons significantly improves the reeling performance and quality of raw silk produced compared to pan cooking.

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  The process of killing the pupa in multi-bivoltine cocoons using salt and hot air drying methods were studied for its influence on reeling performance and quality of raw silk. The cocoons packed with salt in a bag was found to suffocate the pupae and kill them but the reeling performance and quality of raw silk was found to be deteriorated compared to hot air drying of cocoons. Compared to salt drying the hot air drying was found to harden the sericin uniformly thereby improving the reeling characteristics viz., reelability percentage and reducing the waste percentage on silk weight and pelade weight. Further, the quality characteristics viz., neatness, cleanness, tenacity and cohesion were improved by hot drying of cocoons compared to salt drying method. The raw silk percentage, raw silk recovery percentage and elongation of raw silk did not alter significantly by both the methods of drying. The study clearly revealed that hot air drying of multi-bivoltine cocoons significantly improves the reeling performance and quality of raw silk produced compared to cocoons dried using salt.

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[in Japanese]

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[in Japanese]

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  Influence of cocoon cooking condition and reeling basin water temperature on reeling characteristics has been studied for Indian Bivoltine hybrid cocoons. Study has been carried out using two cooking method viz. Single pan and Pressurised, and five levels of basin water temperatures viz, 30℃, 40℃, 50℃, 60℃ and 70℃. It is observed that both cocoon cooking condition and reeling basin water temperature have significant influence on reelability, non broken filament length, raw silk percentage and thread troubles during reeling. Single pan cooking method and low basin water temperature of　30℃ affect the reelability, non broken filament length and raw silk percentage significantly. Whereas higher reeling basin water temperature of 60℃～70℃ increases the thread troubles and sericin dissolution during reeling. Results indicate that cooking of cocoons to the required level and reeling basin water temperature of 40℃～50℃ are the essential factors for achieving better quality characteristics of raw silk.

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  Influence of cocoon cooking condition and reeling basin water temperature on quality characteristics of raw silk has been studied for Indian Bivoltine hybrid cocoons. Study has been carried out using two cooking methods viz. Single pan and Pressurised, and five levels of basin water temperatures viz, 30℃, 40℃, 50℃, 60℃ and 70℃. It is observed that both cocoon cooking condition and reeling basin water temperature have significant influence on neatness, cleanness, tenacity and elongation and cohesion of raw silk. All these characteristics have been found to be significantly better in the case of pressurised cooking and 40℃ reeling basin water temperature as compared to those of other conditions. It is observed that single pan cooking associated with low basin water temperature of 30℃ have affected the neatness, cleanness, elongation and cohesion of raw silk significantly. Whereas pressurised cooking method associated with higher basin water temperature of 60℃～70℃ affected the cleanness, elongation and cohesion of raw silk significantly. Results indicate that cooking of the cocoons to the required level and maintaining the medium basin water temperature of 40℃～50℃ is essential for producing better quality raw silk.

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[in Japanese]

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[in Japanese]

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[in Japanese]

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  Japanese paper yarn has the characteristics such as a stiffness which another natural fibers don't possess, a keeping warmth, no occurrence of the static electricity, a biodegradability. In addition, it is comparative strong against a friction and washable, so it has become to be estimated as the durable products. In this study, in order to add the specific characteristics of silk such as a flexibility with soft feeling and a luster and so on to Japanese paper yarn, the authors produced a hybrid silk which is intertwined with cocoon filaments around Japanese paper yarn as a core. The authors investigated the relationship between the twisting conditions of hybrid silk and the physical properties, bulkiness, luster etc. As a result, a suitable twisting conditoin that the tenacity and elongation would not only reduce so much by twisting and degumming, but also the luster would be comparative high, was 200T/M in the experiment. Under this twisting condition, Japanese paper yarn and the hybrid silk yarn were knitted by using the flat knitting machine and the fully nonsewing computerized flat knitting machine. As a result, it was confirmed that the hybrid silk was knitted easier and more stable than the pure Japanese paper yarn, because the hybrid silk was more pliable than Japanese paper yarn. : New Silk Materials Laboratory, National Institute of Agrobiological Sciences (NIAS) : 1-4-8, Gohda, Okaya, Nagano Pref., 394-0021, Japan

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[in Japanese]

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  There are 70 of the Chinese improved silkworm races (the group of these races is a group of the regional silkworm races) in the silkworm races maintained as the genetic resources at National Institute of Agrobiological Science, Japan. The data on the cocoon qualities of 55 races have been collected among 70 races. The quantitative characteristics of Chinese improved races have been clarified by the correlation analyses among many cocoon qualities. The quantitative characteristics were condensed into a few overall characteristics by 'Maltivariate Anaiysis'. Futher, the correlations between the overall characteristics and the quantitative characteristics were clarified. In conclusion, we examined the quantitative characteristics of the Chinese improved silkworm races by the interpretation of the overall characteristics from the viewpoint of filature.

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[in Japanese]

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[in Japanese]

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  In order to analyze and simulate non-stationary (average) time series with finite length, ladder auto-regressive model was analyzed, and its availability was proved. Statistical characteristics of size curves of cocoon filaments were obtained as criterions of transformation and simulation. Size curves of cocoon filament were unified with their lengths; their trend part and stochastic part were extracted by use of relativity analysis theory. The stochastic part was normalized thereby was regarded as stationary (average) time series with finite length in this paper. Using ladder autoregressive model, the simulation was done, generated time series was reverse normalized for obtaining the stochastic part. Simulated size curve of cocoon filament can be obtained by adding generated stochastic and trend part and inverse unifying the length. According to the result of experiment simulated on personal computer, it is believable that the method proposed in this paper is available.

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[in Japanese]

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