• Journal of the Korea Academia-Industrial cooperation Society
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• v.10 no.2
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• pp.412-417
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• 2009

In order to investigate the effective sericin fixation of raw silk fibers the influence of various additives added to the melamine and formalin mixtures on sericin fixation was studied. When raw silk fibers were treated with wetting agent but without subsequent washing before sericin fixation, the strong sericin fixation was obtained by fixing sericin. Adding hydrogen peroxide to the melamine and formalin mixture made sericin fixation worse, resulting weaken the sericin hardness of fixed raw silk fibers and tight bonding of the fibers. On the other hand, it was confirmed that adding sodium hydrosulfite to the melamine and formalin mixtures gave better sericin hardness of fixed raw silk fibers without the bonding of fibers. Supplying additional melamine with he low concentration of sodium hydroxide to the melamine and formalin mixture(melamine:formalin= 1:6) resulted in very good sericin fixation. But adding hydrochloric acid or methanol to the same mixture had no effect on the sericin fixation, and adding magnesium chloride to it made the hardness of sericin fixation even worse.

• International Journal of Industrial Entomology and Biomaterials
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• v.41 no.2
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• pp.51-55
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• 2020

The objective of this study was to evaluate the changes in gene expression after incubation of cells with soluble fraction from different silk mat layers. A silk cocoon from Bombyx mori was separated into 4 layers of equal thickness. The layers were numbered from 1 to 4 (from the inner to outer layer). Each silk mat was placed into normal saline and collected soluble fraction. They were administered to RAW264.7 cells, and changes in the expression of genes were evaluated by cDNA microarray analysis. Layer 1 and 4 groups showed significantly higher expression of BMP-2 at 8 h after administration of soluble fraction (P < 0.05). Runx2 expression was significantly higher in Layer 4 group at 8h (P < 0.05). The silk mat from the innermost and outermost portion of the silkworm cocoon showed a significant change in the expression of genes that are associated with osteoinduction such as BMP-2 and runx2.

• Korean Journal of Human Ecology
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• v.7 no.1
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• pp.43-50
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• 2004

The purpose of this study is to reach silk protein added in differing amounts to Jeolpyon, Korean traditional rice cake, using rice powder as its primary material, estimation of the micro organism quality, physicochemical property, sensory evaluation and the property of storage period (20${pm} 5 ^{\circ}C$). In the physicochemical property, the content of proximate composition of rice powder was measured as 38.11% of moisture, 56.62% of total sugar, 5.11% of crude protein, 0.52% of crude lipid, 0.25% of ash. And the raw material of silk protein was measured as 6.61% of moisture, 91.22% of crude protein, 6.41% of crude lipid and 0.75% of ash. The pH of raw material for rice powder and silk protein Jeolpyon showed mild acidity as 6.41 and 6.23, respectively. In rice powder and silk protein, total free sugar contents was 0.89% and 0.02%, and total amino acids contents was 4.28% and 52.21 %, respectively. For sensory evaluation. color, taste, softness and adhesiveness were significantly acceptable in control and adding 1 % silk protein. Control and samples added 1$\sim$3% silk protein had high sensory score color in overall acceptance. In conclusion. Jeolpyon can be manufactured with nutritious Jeolpyon by adding silk protein.

• Journal of Sericultural and Entomological Science
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• v.4
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• pp.63-68
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• 1965

This treatise was carried out to study the hereditary phenomenon of silk lousiness and the interaction of genes related with silk lousiness. It was also studied how to improve the silk lousiness of general raw silk by refining process because the selective process was found as unsatisfactory method. The conclusions reached were as follows. A. Conclusions related with genetic problem. 1. The decreased effects of the lousiness were 11 % in the F$_1$ hybrids. 2. Lousiness was considered to inherit as the incomplete dominance. 3. The effects of the lousiness gene were additive, and the lousiness of raw silk might be influenced by more than two genes. 4. The quantitative characters of cocoons were not genetically correlated with the occurrence of lousiness. 5. Lousiness could not be said to occur more in the heavy-cocoon strains. 6. The microscopic lousiness test of this paper showed the same result of the international exforiation test. B. Conclusions related with lousiness improvement. 1. Raw silk was able to be refined by the employment of 0.2% cationic softener solution for 30 minutes at 95$^{\circ}C$, supressing the occurrence of lousiness. 2. Anionic chemical softener was not available for silk refining process. 3. The above cationic softener refining prosess did not cause any physical defect for the silk fiber. 4. Soap refining process caused silk lousiness easily.

• Journal of Sericultural and Entomological Science
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• v.17 no.1
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• pp.1-26
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• 1975

These studies were attempted to find out the optimum silk reeling system by use of automatic silk reeling machine to increase raw silk yield and reeling efficiency with various silk reelable cocoons. The obtained results are as follows; 1. The mean silk reelability ratio(X)of the Korean cocoons during the last ten years was 61 per cent, beside 64.7 per cent in autumn cocoon and 57.3 per cent in spring cocoon. However, the ratio variation of autumn cocoons was larger than that of spring cocoons. 2. A positive correlation between cocoon filament breaks during its process and silk reelability levels was shown to be significant. The cocoons of both poor and good reelability evidenced "J" shape distribution on the filament break graph by the order of reeling cocoon end. Many bave breaks were found at the inner shell of the cocoons, or in case of poor reelability cocoons. 3. The morphology of broken cocoon ends during the process was classified into A, B, C, D, E and F types, The occurrence of B type was majority, but that of F type was minority among them. 4. In case of the cocoon cooking, H-type ion-exchanged soft water was better for good reelability cocoons, Na and H-type ion exchanged neutral soft water for those of fair reelability, and alkaline (Na-type) soft water for those of poor reelability, respectively. 5. The modification of cooking water by mixing the above different types of water (50％ Na-type and 50％ H-type passed by standard natural water; 75％ Na-type and 25％ H-type passed by hard natural water; 25％ Na-type and 75％ H-type passed by soluble natural water) made higher yield of raw silk with tess breaks of thread. 6, In case cocoon ends groping water included sodium hexametaphosphate as much as 800 ppm. the groping efficiency and raw silk yield of cocoon was improved. The effect was pronounced in case of poor reelability cordons. 7. The most reasonable cocoon cooking and silk reeling condition for automatic silk reeling process were observed to be rather incomplete cook with good reelability cocoons and optimum cook with poor reelability cocoons succeeded by the reeling bath temperature of 45$^{\circ}C$, 8. The reasonable silk reeling velocities were observed to be about 150m per min. for good reelability cocoons, 120m per min. for fair reelability ones and 90 to 120m per min. for poor reelability ones. 9. In order to improve the raw silk yield of cocoons and reeling efficiency, the cocoon stand-by-ratio for reeling should be kept at the level of 40 per cent for good reelability cocoons or at 60 per cent for poor reelability ones beside necessary end found cocoon condition.

• Journal of Sericultural and Entomological Science
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• v.47 no.1
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• pp.41-47
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• 2005

Kayagum is a traditional musical instrument in Korea. Kayagum strings are usually made of raw silk. It needs good vibration and durability. This study was carried out to increase durability of the strings by chemical treatment and manufacture of silk/polyester and silk/wild silk compound yarn. In this study, we used MKW-810(water solube acrylic adhesive)and polyvinyl alcohol as a adhesive. Before the twisting, the raw silk wet on the string manufacture process. The adhesive reagent were added in this process. And compound yarn were prepated by domestic silk, polyester and wild silk(antheraea pernyi) for make of Kayagum strings, respectively. The result are as follows. 1. Tenacity and elongation of the strings are almost same between none and chemical treatment. However number of extension cycling to breaks of the strings was largely increased by chemical treatment. Number of extension cycling to breaks of the strings is very important and useful item to check durability of the strings. The stiffness of the strings were almost same between none and adhesive treatment 2. Tenacity of the silk/polyester strings is largely decreased by increasing of polyester portion, but elongation of the silk/polyester strings increased. However tenacity of the silk/polyester(mono filament) strings are higher than that of silk strings. 3. Tenacity of the domestic silk/wild silk strings is largely decreased by increasing of wild silk portion, but elongation of the domestic silk/wild silk strings is almost same among silk and domestic silk/wild silk strings.

• International Journal of Industrial Entomology and Biomaterials
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• v.14 no.1
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• pp.23-32
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• 2007

The nature of genetic variation and diversity among the 65 multivoltine silkworm genotypes was evaluated for 16 post cocoon characters. The components of genetic variation revealed higher PCV (60.487%) and GCV (44.56%) for evenness (variation 1) followed by cohesion (PCV=55.38%, GCV=40.36%) and non-broken filament length (PCV=32.05%, GCV=31.28%). The higher heritability ($h^2$ in broad sense) was observed for boil-off loss (95.6%) followed by non-broken filament length (95.22%). The both genotypic and phenotypic correlation indicated significant positive correlation of filament length with non-broken filament length, silk recovery, raw silk, neatness, and low neatness; and negative correlation with denier, renditta and silk waste. The principal component analysis (PCA) revealed 75.381 % of total variance from the five principal components extracted. On the basis of Mahalonobis' $D^2$ values (Ward's minimum variance), the sixty-five multivoltine silkworm genotypes were classified in to 9 clusters with substantial inter and intra cluster distances. Number of genotypes included in different clusters varied from 3 to 17. The results indicated that the optimum distance obtained in cluster VII (15.059) along with higher cluster mean values especially for filament length, non broken filament length, renditta, silk recovery, silk waste, and raw silk emphasized the utilization of these genotypes in the conventional silkworm breeding programme for improvement of multivoltine silk fibre quality. The possibility of exploiting genetic variation in post cocoon traits for efficient breeding programme is discussed.

• Journal of Sericultural and Entomological Science
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• v.34 no.1
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• pp.57-71
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• 1992

These studies were carried out to establish Korean opinion about "The electronic method of raw silk testing and grading" which was taken shape along with the report by Silk Standard Committee(S.S.C.) at the meeting of International Silk Association(I.S.A) Directing Board session held in Zurich Swiss. This establishment was througly examine whether or not the above are the essential factors to be fulfilled in force as a international standard method of raw silk testing and grading.d grading.

• Journal of Sericultural and Entomological Science
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• v.20 no.2
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• pp.40-44
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• 1978

Cerium (IV) ion-initiated graft copolymerizations of acrylonitrile to raw silk were investigated in an effort to carry out sericine-fixation. The change in ceric ammonium nitrate concentration exhibited a maximum in percentage of grafting at 0.003M. Also observed was that the change in nitric acid content in reaction media gave a maximum in percentage of grafting at 0.1M. Percentage of grafting was increased generally with increase in acrylonitrile concentration, reaction time and reaction temperature. Raw silk sericin grafted with acrylonitrile was not de gummed by boiling off test and optimum graft percentage was considered at 20%.

• Journal of Sericultural and Entomological Science
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• v.27 no.1
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• pp.47-50
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• 1985

The physical properties of graft polymerized silk fibre were investigated with various vinyl monomers. 1. The graft polymerization of styrene and methyl methacrylate onto raw silk reduced the tenacity and elongation of raw silk due to fixation of sericin covering silk fibre in, but the styrene grafting was more effective for sericin fixation of raw silk than the methyl methacrylate one. 2. The water absorbability of glycidyl methacrylate grafted silk increased 14.6% greater than that of methyl methacrylate grafted silk at the same degree of grafting polymerization. 3. The degree of grafting polymerization was increased mostly with ethylene glycol methacrylate. The water absorbability of ethylene glycol methacrylate grafted silk was higher than that of glycidyl methacrylate or ethyl acrylate grafted silk. But the grafted silk fabric increased the fabric flexural rigidity which was negatively related with the favorability of fabric hand-touch, as compared with that of nongrafted silk fabric. 4. The evenness of graft polymerization could be improved by agitating the polymerization bath at the fixed interval by reducing the inter size deviation of grafted silk skein and the thickness deviation of grafted silk fabric.