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

• Animal cells and systems
• /
• v.7 no.1
• /
• pp.35-41
• /
• 2003

The principal fibers used in constructing the cocoon in the garden spider, Argiope aurantia, are large-diameter fibers developed from tubuliform glands and small-diameter fibers presumed to be spun by the aciniform silk glands. Scanning electron micrographs of the large-diameter fibers on both surfaces of the cocoon clearly reveal their fine structural differences. While the silk fibers on the inner surface have smooth and homogeneous appearances, each fiber on the outer surface represents a multicomponent internal structure. Examination of each fibers using transmission electron microscope also provides additional evidence that the multicomponent fibers contain numerous electron lucent fibrils embedded in an amorphous electron dense matrix. It has been also revealed that two types of secretory granules presumed to be the precursors of tubuliform fibers are closely related to the production of distinct coloration in luminal contents - brownish and yellowish components. Moreover, these electron-dense granules, possibly precursor of fibrillar component, and electron-lucent granules, possibly precursor of matrix component, are densely packed and remain close to each other without fusion. It is critical evidence that the individual tubuliform fiber is not only heterogeneous and multicomponent but also takes place in a variety at manners throughout the length of the gland.

• Journal of Sericultural and Entomological Science
• /
• v.40 no.1
• /
• pp.70-77
• /
• 1998

This study was carried out in order to find out the relationship between physical and chemical properties of silk fiber treated by concentrated calcium nitrate solution. The tensile, thermal and dynamic mechanical properties are also examined on Ca(NO3)2 treated silk fibers. The tensile properties of silk fibers treated by calcium nitrate changed with a concentration. The thermal behavior were also affected by the concentration of calcium nitrate. The degradation temperature (endotherms) and glass transition temperature shifted to lower temperature as the treated concentration increased. It is thought that the physical properties are strongly related to the structure and morphology of Ca(NO3)2 treated silk fibers. As a result, these give property changes with a concentration dependence.

• Journal of Fashion Business
• /
• v.9 no.1
• /
• pp.57-66
• /
• 2005

In natural dyeing, a number of supplementary methods have been practiced since deep shades of the dyed fabrics are not developed satisfactorily. The methods include using the mordants effectively or subjecting the fabrics to reiterated dyeing processes. In this study, we obtained deep shades in the dyeing of fabrics using Rhusjara ica as the dyestuff and applied chitosan to the fabric specimens in order to diversify the colors. Silk fibers and PET(polyethylene terephthalate) fibers were pretreated using chitosan, and subsequently dyed using different types of mordants. As the mordanting agents, Al, Sn, and Fe were employed. Various shades have been resulted in since the interactions of the mordants are different toward the silk fibers and PET fibers. In this study, we investigated the effect of the chitosan treatment along with the change of the mordanting agents on the color change for the silk and PET fibers.

• Textile Coloration and Finishing
• /
• v.5 no.2
• /
• pp.99-108
• /
• 1993

In one dyeing system of silk/synthetic blend fabrics (polyester, nylon, acetate) with acid dyes/disperse dyes, dyeability and desorptibility of disperse dyes on silk fabric and transfer from dyed silk fabrics to synthetic fabrics by color difference were examined. When silk dyed with C.I. Disperse Red 19 and C.I. Disperse Red 60 at 10$0^{\circ}C$ for 60 minutes, color difference of dyed silk were $\Delta$E=56.72, $\Delta$E=47.65 for blank silk, respectively. The desorption rate of the dyed silks were measured in boiling bath with and without dye-free synthetic fibers. The desorption rate of dyed silk was effected by affinity of synthetic fabrics contained. When silk dyed with Red 19 and Red 60 was reduced at 10$0^{\circ}C$ for 60 minutes, the decolouration rates of dyed silk were 75% and 40%, respecdtively.

• International Journal of Industrial Entomology and Biomaterials
• /
• v.13 no.1
• /
• pp.45-50
• /
• 2006

Papers were prepared from cut cocoons and mulberry branches, which are byproducts from sericulture industry. The long filament of silk should be cut into appropriate length in order to prepare paper and this was achieved by chemical method. By a mixture of sodium hydroxide and sodium carbonate solution, the silk filaments were cut into short fibers (less than 1 mm in length). Since the short silk fibers (sSf) could not bind each other by itself, starch and poly(ethylene oxide)(PEO) were added as a bonding agent. When starch and PEO were used in a ratio of 3:7, the silk papers had optimum mechanical properties for paper. Fibers from the skin of mulberry branches (MBF) were added to sSf to enhance the mechanical properties of pure silk paper. Bleaching of MBF was performed with a mixture of hydrogen peroxide and sodium silicate. The mechanical properties were greatly enhanced and the optimum blend ratio of MBF and sSf were 7:3. The mulberry/silk paper has good absorption property against formaldehyde, and therefore, the paper could be applied as a wall paper for preventing the sick house syndrome.

• International Journal of Industrial Entomology and Biomaterials
• /
• v.26 no.1
• /
• pp.54-60
• /
• 2013

The partial degumming of silk has recently attracted researchers' attention because of its ability to produce silk textiles with new tactile properties, intermediate between the softness of fully degummed silk and the hardness of raw silk. However, it is difficult to obtain partially degummed silk in a homogenously degummed state due to the heterogeneous character of sericin removal. It is also difficult to examine the homogeneity of degumming. In the present study, Fourier transform infrared (FTIR) spectroscopy with attenuated total reflection (ATR) geometry was used to evaluate the effect of processing conditions on the degumming of silk yarns. The crystallinity index, calculated from FTIR spectra, showed an increase with the degumming ratio. Therefore, the homogeneity of degumming could be evaluated by the variation of crystallinity index for 30 different spots in silk yarns. The homogeneity of degumming was influenced by the total degumming time, the content of surfactant, and the liquor rate. No effect was observed upon changing the number of degumming cycles at the same total degumming time.

• Textile Coloration and Finishing
• /
• v.18 no.5 s.90
• /
• pp.8-14
• /
• 2006

An earthworm protease, Lumbricus rubellus, was used to improve the dyeing properties of protein fibers such as wool and silk. The optimal condition for the activity of the earthworm pretense was about $40^{\circ}C$ at pH 7. The wool and silk were treated with the protease extracted from an earthworm and the K/S values of the dyed wool and silk were measured using a spectrophotometer in order to compare the dye uptake. The pretense treatment enhanced the dyeing properties of protein fibers without severe changes in mechanical properties. The surface appearances of pretense-treated fibers were observed by microscopy analysis.

• Journal of Sericultural and Entomological Science
• /
• v.34 no.2
• /
• pp.32-40
• /
• 1992

Many studies have been carried out on the graft finishing in order to improve the quality of silk fiber. Various vinyl monomers, for instance, styrene, methylmethacrylate, 2-hydroxyeth-ylmethacrylate and methacrylamide, have been used practically up to date. Among these monomers, methacrylamide has been applied as the most favourable monomer onto silk fibers in recent years. The polymerization mechanism about styrene- and methylmethacrylate-grafted silk fiber has been studied by many researchers. They proposed that free radicals were formed and vinyl monomers were polymerized in silk fibroin by graft polymerization mechanism, while active sites were varied by the types of monomer and initiator as well as by the reaction condition. In general. there is another Opinion that monomers are polymerized and impregnated in the internal side of the fiber by homopolymerization, which has not been proved experimentally yet More than 10 years have been passed since methacrylamide was applied on the silk fiber, and at the present time most finishings are being achieved by methacrylamide. However, no attention has been paid to the polymerization mechanism of the methacrylamide-treated silk fiber yeL In this paper, the treatments of methacrylamide on silk fibers were studied in aqueous solution using potassium persulfate as an initiator. The polymerization mechanism of the methacrylamide-treated silk fibers was investigated and analyzed on the basis of the results of infrared spectroscopy, amino acid analysis and scanning electron microscopy. From the results of these instrumental analyses, it can be suggested that polymerization mechanism about the methacrylamide-treated silk fibers is not performed by graft polymerization which has been accepted generally in styrene and methylmethacrylate-grafted silk fibers. The different mechanism is supposed to be due to the difference in monomer types, initiator types and treatment conditions.

• Journal of the Korean Society of Clothing and Textiles
• /
• v.13 no.4
• /
• pp.370-379
• /
• 1989

In previous paper, the optical behavior of coloring matter of Cromwell under several conditions were investigated. In this paper, the fading behavior of color solution extracted from Growell by methanol, dyeing properties of this color on the silk fibers in water and methanol, the three property of color of dyed silk fabrics, and fading behavior of dyed silk fabrics with Cromwell color under light and washing were discussed.