The expansion of other industries and the development of urbanization resulted in changes in the industrial structure of the Isesaki textile and fabric production area. At the same time, there was a large reduction in the number of textile enterprises and a decline in the textile industry’s role in the regional economy. The attenuation of the textile industry highlighted the following problems regarding its production structure, namely the gradual reduction in the size of enterprises, the aging of the workforce and the serious shortage of replacements, and the weakening of the infrastructure. There are at least three ways to promote future production in the Isesaki area: First, with the opportunity provided by the ‘Meisen’ boom, various kinds of new products should be created utilizing the ‘Meisen’ technologies, which should not be limited solely to the production of kimono. Second, with the continuing attenuation of the textile industry zone, it is very important to rebuild peer awareness among counterparts in the textile industry in Isesaki. Third, it is also very important in Isesaki to use the excellent characteristics of ‘Meisen’ as a lever, and to teach and advertise ‘Meisen’ techniques to young people and thus secure successors to continue the textile industry. (Naotatsu Ono, Email: ptokotoko@tbn.t-com.ne.jp)

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The purpose of this article is to clarify the position of the necktie sector and the management strategies of the weaving industry in the Nishijin textile production area. The analysis presented in this article reveals that the entire scale of production in the Nishijin production area was shrinking along with that of other production areas after 1975, as the demand for kimonos decreased. It is also pointed out that increasing variety of neckties produced by using a wide range of material and positively developing a new market are management countermeasures to ensure the survival of many particular textile enterprises. Furthermore, two points regarding the direction of future development can be pointed out: Firstly, although the promotion policies for Nishijin from the consumer’s viewpoint can be seen in the 6th vision, it must also be emphasized that the producers should produce neckties that consumers want to use increasingly in their daily lives after using them once. Secondly it is very important to strengthen the understanding between the necktie sector and other related sectors concerning each other’s real situation with respect to production and circulation in tems of peer awareness. (Naotatsu Ono, Email: ptokotoko@tbn.t-com.ne.jp)

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Different types of mountages were tested to determine the comparative reeling and raw silk quality characteristics of cocoons produced using them. The five types of mountage used in the study were the vertical fixed mountage, the shoot rearing rack rotary mountage, the traditional bamboo mountage, the rotary mountage and the plastic collapsible mountage. The results indicated that the highest percentage of defective cocoons was found with the plastic collapsible mountage (16.8%) followed by the conventional bamboo mountage (12.7%), the vertical fixed mountage (7.7%), the shoot rearing rack rotary mountage (5.6%) and the rotary mountage (3.8%). The cocoons harvested from the rotary mountage exhibited the highest quality. The reelability was found to be greater than 85% for all mountage types except for the collapsible plastic mountage (77%). The percentage of raw silk obtained was highest with the rotary mountage (17.4%) and lowest with the plastic collapsible mountage. From the results it can be inferred that under given temperature and humidity conditions, the quality of the raw silk production depends strongly on the mountage used as well as on the silkworm genus being reared. It was observed that the raw silk produced using the plastic collapsible mountage was inferior to that produced with the other mountages used in the study. (*: To whom correspondence should be addressed, Tel +91-80. 26282156, E-mail: shillin_sn@yahoo.co.in)

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The purpose of this study is to suggest cooking parameters for semidried bivoltine hybrid cocoons and thus achieve better reeling performance and quality characteristics for raw silk by reeling it on a CSTRI multi-end reeling machine. The effect of the duration of high temperature steam treatment, the steam cooking duration and the temperature profile of the adjustment treatment of cocoon cooking on the reeling performance and quality characteristics of raw silk obtained from semidried bivoltine hybrid cocoons has been studied using a CSTRI stationary circular cocoon cooking machine. Cocoons were reeled on the CSTRI multi-end reeling machine. It was observed that all the above three cocoon cooking parameters have a significant influence on reelability, raw silk recovery and waste % on silk weight. Results indicate that the duration of the high temperature treatment and steam cooking treatment play a dominant role with respect to the cleanness, elongation and cohesion of raw silk, whereas the temperature profile of the adjustment treatment has a significant influence on all the quality characteristics of raw silk. It is also observed that the cooking parameters have a significant influence on thread troubles during reeling. Based on the study, cooking parameters have been suggested with a view to achieving better results from semi-dried cocoons. (*To whom correspondence should be addressed, Tel +91-8559-222284, E-mail: naikcstri@yahoo.co.in)

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This experiment was conducted to investigate the distribution of flavonols in the yellow green Irodori cocoon, a flavonol rich cocoon harvested in Saitama Prefecture. A free flavonol fraction was prepared by extraction from cocoon shells in 80% methanol. The shells that remained after removing the soluble flavonol were boiled in hot water at 115°C for 30 min to separate sericin and fibroin fractions. The flavonol content in the three fractions, i.e., the free flavonol fraction, sericin fraction, and fibroin fraction, were found to be quercetin equivalent by measuring absorbance at 365 nm. The results were 2227, 132 and 226 µg/g cocoon shell, respectively. It was found that the Irodori cocoon remained yellow after the removal of free flavonol, suggesting that some flavonol resistant solubilization may closely be associated with silk protein. (E-mail: yamazaki@silk.or.jp)

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Cotton fabrics were treated with sericin and citric acid solution (SC) to improve resistance to wrinkles and limit dimensional changes in cotton fabrics. The cotton fabrics were subjected to crease recovery and a series of washing and drying cycles in a household washing machine, and examined for dimensional changes. An SC treated blouse was subjected to home laundering to evaluate its durability when washed. An untreated cotton fabric (control) blouse and a blouse prepared for easy-care processing (EC) were also used for comparison. The SC treated cotton fabric exhibited high crease recovery and elastic recovery percentage by extension than the control cotton fabrics. The SC treated cotton fabrics had shrunk less than the control cotton fabrics after ten washings. Although the dimensions of the EC blouse changed less than those of the EC blouse, it was thought that the SC treated blouse was synthetically equal to the EC blouse. (*: To whom correspondence should be addressed, E mail: fkurioka@silk.or.jp)

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A computer simulation experiment was performed to examine the reliability and repeatability of the classification of the evenness variation Ⅱ test for raw silk in China. As the applicable grade was low, the sampling error was large for the standard deviation and small for the coefficient of variation. The appearance of the applicable grade was 46% for the same grade, 48% for differences in grade 1 and 6% for differences in grade 2. The probability of a defference in grade was 54%.
For repeated testing of the same lot, the differences in applicable grade were 34% for the same grade, 51% for differences in grade 1, 13% for differences in grade 2 and 1% for differences in grade 3. There was a 66% probability of there being a defference when grading twice. There was a marked difference between the experimental and calculated values. (Email : kouzu_ub@nifty.com)

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The physical properties of plain silk fabrics (Habutae), which were prepared by grafting with methacrylamide (MAA) or 2-hydroxyethyl methacrylate (HEMA) were analyzed using KES system equipment. The B and 2HB values for MAA grafted silk fabrics increased slightly with increasing fiber weight, while the B value for HEMA grafted silk fabrics increased sharply after the grafting, when the weight increased up to 50%. The TO values of MAA grafted silk fabric increased, suggesting that the silk fabric became bulky. The G and 2HG values for HEMA grafted silk fabrics with a weight gain of 50% could not be correctly measured, because the silk fabric became excessively stiff. This probably accounts for the binding HEMA homo-polymers copolymerized on the surface of the silk fabric. (*E-mail: tsukada@shinshu-u.ac.jp)

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We succeeded in producing fireproof silk fabrics using grafting techniques with phosmer compounds. The optimum initiator and monomer concentrations were 3%owf and 60-100%owf, respectively. After grafting with phosmers M and CL, the tensile strength of silk fiber increased about 20% and elongation decreased about 30%. The morphology of the silk fiber remained unchanged after grafting. Silk fabric grafted with phosmers M and CL exhibited a major endothermic peak at 345°C, attributed to thermal decomposition, that was 30°C higher than that of the control specimen. A JIS fire retardation test showed that grafting phosmers M and CL to silk fabric was effective as a fireproofing technique. (*E-mail: tsukada@shinshu-u.ac.jp)

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Cocoon shells exhibiting yellowish white fluorescence (F-YW) and dark blue fluorescence (F-DB) were selected from a commercial strain (Kinsyu × showa) under UV excitation, and the factor(s) responsible for the distinctive difference between the colors of F-YW and F-DB was studied. In F-YW, an ethanol soluble material with yellowish white fluorescence was detected in the sericin layer at a length of 600 to 800m from the surface of the cocoon shell whereas no such material was found in F-DB. This result indicated that the yellowish white fluorescent material deposited in the middle layer of the cocoon shell affected the fluorescence of the cocoon shell. Based on a fluorescence spectrophotometric analysis and DPPH assay, the yellowish white fluorescent material in F-YW was thought to be different from the flavonols found in the Irodori cocoon. The three-dimensional fluoresce spectra of F-YW were distinct from that of F-DB, and fluorescent emissions at 425 and 540 nm in F-YW may be responsible for the yellowish white fluorescent color of the cocoon shell. (E-mail: akurioka@silk.or.jp )

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Cotton fabrics were treated with sericin (1.2%) solution containing citric acid (9%) as a cross-linkage agent to improve their hydrophilic and thermal properties. The treated fabrics absorbed more water than the non-treated fabrics, and the water diffusion time decreased. The moisture content and maximum absorption coefficient of the treated fabrics were much smaller than for untreated fabrics. Moreover, the q-max, thermal conductivity and air permeability resistance values were larger. (*: To whom correspondence should be addressed, E-mail: fkurioka@silk.or.jp)

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The aim of this study was to manufacture artificial hair from raw silk fiber. Some artificial hair is heavy, and not hygroscopic. Raw silk fiber of Gunma×200 was used for the artificial hair. The mechanical properties of raw silk fiber and human hair were examined. As regards raw silk fiber, the expansion rate was inferior to that of hair. The raw silk fiber underwent salt shrinkage treatment. The salt shrinkage treatment was performed in an aqueous solution of calcium nitrate with a dipping and heating method. The specific gravity of the processing solution was 1.4. The treatment temperatures were 70, 75, and 80°C. The treatment time was two minutes. The raw silk fiber was curled by the salt shrinkage treatment, and it also shrank. The expansion rate of the raw silk fiber was increased by the salt shrinkage treatment, as was that of the human hair. The surface structure of the raw silk fiber after the salt shrinkage treatment was observed with a scanning electron microscope. The artificial hair became bunched as the filaments of raw silk curled. The artificial hair was obtained using Gunma×200 and salt shrinkage treatment, and so it will be possible to develop a manufacturing process.

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Activated carbon was prepared by using four kinds of cocoons. The cocoons were heated to 400°C and carbonized. The carbonized cocoons were then soaked in potassium carbonate solution. The activated carbon was obtained by heating these carbonized cocoons at 800°C for 1h. After the activating treatment, the specific surface areas of these cocoon were 2000-2600 m²/g, and efficient activated carbon was obtained. Of the four kinds of cocoons, the specific surface areas of Gunmakogane and Shinseihaku were found to be higher. These activated carbons maintained the shape of the cocoon. The kind of cocoon did not affect the carbonization, and it was easy to produce efficient activated carbon with a specific surface area of 2000-2500 m²/g or more.

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The physical properties of silk fibroin/chitosan composite films were examined by using FTIR, DSC, TMA, WAXD measurements. The FTIR spectra of the composite films revealed overlapping absorptions that were attributed to silk fibroin and to chitosan. The DSC curve of the composite film (SF90/CS10) overlapped the DSC curves of silk fibroin and chitosan. The length of the silk fibroin film extended above 175°C (first extension temperature) and above 270°C (second extension temperature), exhibiting thermal instability as regards sample length during the heating process. The length of composite films containing high amount of chitosan did not extend even at the first extension temperature, suggesting increased thermal stability. The X-ray diffraction (WAXD) profiles of the composite films overlapped the diffraction curves of silk fibroin and of chitosan. The elongation when the silk fibroin film broke was as low as 0.7%, suggesting very brittle tensile properties. The elongation when the silk fibroin/chitosan composite films broke increased as the chitosan content increased, thus implying an enhancement in the elongation of the composite films with increasing chitosan content. (*E-mail: tsukada@shinshu-u.ac.jp)

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The results of this study were obtained from an investigation of the archives of silk production in relation to the tax on silk during the Nara period in the 8th century. The silk producing districts ranged from the Kanto region to Shikoku and Kyushu, and there were over 40 silk producing districts in the middle of the 8th century. Three main kinds of silk were produced, namely Ashiginu fabrics, silk fiber and floss silk, and there were 15 districts producing Ashiginu fabrics (42%). The districts producing the largest amount of silk annually were Echu (floss silk), Inaba (Ashiginu fabrics, silk fiber and floss silk) and Iwami (floss silk). The districts that were the largest annual producers of the three different types of silk were Mikawa (Ashiginu fabrics), Inaba (silk fiber) and Echu (floss silk). Mulberries were cultivated in Echu district in 759 A.D. and this was the only example of mulberry field cultivation in the Nara period. Two hamlets in the Echizen district in 740 A.D. were the only locations where sericulture was practiced in the Nara period. These were produced against the tax of silk by Ashiginu fabrics and floss silk. And the weights of these products were 2.4 and 1.8kg, respectively, and the used cocoon weights were 40 and 30 kg, respectively, from a trial calculation for harvesting cocoons. Moreover, the total harvesting cocoon were about 80 and 90 kg by addition to Ashiginu fabrics. (E mail: mutsuo_miki@yahoo.co.jp)

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